This reverts commit 55a8b15.

* documentation update for keyword arguments

* Update README.md

* Update CHANGELOG.md

#381)

* add a scope class to manage the context of interaction with Python and simplify the variable exchanging

* Deprecate public RunString

Had to remove defaults to disambiguate call on `internal RunString`.
Can re-add after removing `public RunString`

Closes #401

* Rename several methods and add three methods

Referring to IronPython, change the name of the methods Get, Exists, SetLocal, DelLocal to GetVariable, ContainsVariable, SetVariable, RemoveVariable.
Hidden the methods SetGlobalVariable, RemoveGlobalVariable.
Add a new method 'Compile' to compile string into ast, the ast can be seen as the ScriptSource of IronPython.
Add two new methods 'Execute' and 'Execute<T>' to execute an ast and
obtain the result, corresponding to the 'Execute' method of IronPython.

* rebased

* Rebased update

* format cleanup

* create unnamed pyscope, make PyScope.GILState save

remove method GetInstHandle
add function to create unnamed pyscope
add a field isDisposed for PyScope.GILState to make it more save

* fixup! create unnamed pyscope, make PyScope.GILState save

* remove GIL and rebased

* Add several methods

add ImportScope: a scope can import variable from any scope, equivalent to
python 'import * from mod'
add dynamic member support
add an OnDispose event
remove the field ‘globals’ referring to python module
put the scope class in a new file

Unit test:
TestThread uses scope function replacing Exec/Eval to speed up the execution.

* add a Variables method

* fixup! add a Variables method

* remove private method _GetVariable

* add unit test for Variables() method

* add several methods and rebased

Add an optional dict parameter for Eval/Exec/Execute methods
Add a new field obj which point to a Python Module (same as pyobject)
Add a static method New
Rename the old ImportScope method to ImportAllFromScope
Add a new ImportScope method and add a unit test for it
Rename the CreateScope method to NewScope

* add a new class PyScopeManager

* cleaned up the Import methods

* updated according to filmor's comments

* fixup! updated according to filmor's comments

* Get/Set Methods renamed

Fix crash of python interpreter 3.5 64-bit in garbage collector

* Fix conversion of 'float' and 'double' values

Fix problem of conversion 'float' and 'double' values in converter.cs.
As there was a range check both for 'float' and 'double' values, which
are less or greater than its 'MinValue' and 'MaxValue' accordingly,
several values like 'float.NegativeInfinity', 'float.PositiveInfinity'
and the same 'double' values cannot be converted from Python to .NET
values.

Add error check after 'PyFloat_AsDouble' call.
Due to Python C API documentation, method 'PyFloat_AsDouble' can return
'-1.0' upon failure. So it requires error check. This rule forces to
check for error and throw exception in case of error.

Add tests, which cover problem of conversion 'float' and 'double'
values.

Resolves: #486.

* Fix failing 'test_double_conversion' test

Fix incorrect part of 'test_double_conversion' test in test_conversion.py.
An 'OverflowError' was expected for valid values, which represent Python
'inf' and '-inf'.
The problem was identified with support of conversion for Python 'inf'
and '-inf' to .NET System.Double PositiveInfinity and NegativeInfinity.

See also: #487.

* Add Runtime.PyObject_IsIterable and fix PyIter_Check for Python 2

* Add test_clrmethod.py and update AUTHORS and CHANGELOG

* Fix test docstrings

* Use IntPtr.Zero instead of null for comparisons with IntPtrs

* Add test on Runtime.PyObject_IsIterable and Runtime.PyIter_Check

* Use the already defined TypeFlags.HaveIter instead of redefining it

* Add PyIter_Check and PyObject_IsIterable tests on threading.Lock, which does not have type feature iter

* Move the tests from test_runtime.py to TestRuntime.py

`PyObject_TYPE` does not `Incref` the type object returned, in contrast
to `PyObject_Type`, which was used here before.

* Add tests of subclassing with __namespace__

* Remove __init__ call from ClassDerived.InvokeCtor

* Trying out __init__

* Cleanup

* Add tests constructing python type from CLR and calling __init__

* Revert borked changelog update

* Don't leak init reference

* Rename tests

* Remove unused internal Runtime.GetBoundArgTuple

* Reenable skipped tests in test_subclass.py

On Windows 64bit systems, a C `long` is a 32 bit integer while the rest
of the world has agreed on making `sizeof(long) == sizeof(void*)`.

* Binary substitution of Python.Runtime.Dll becomes safe.
* Public constants replaced to static readonly fields. Relaxed platform binding.
* Static readonly fields (related to build depented values) replaced by properties.

* Explicitly specify files to upload to codecov

* Produce coverage.xml

* Full featured xplat build.

* .Net 45 TargetingPack System.XML.dll naming fix. (For xplat linux build).

* Setup.py --xplat option refactored. Travis-ci build matrix extended.

* AppVeyor matrix extended, xplat build added.

* appveyor.yml yaml syntax fix.

* NUnit dependency upgraded to 3.7. Changelog improved.

* Build order improvement.

* Mono builds now can be build on Windows.
DEBUG;TRACE fix for the case VS + non empty PYTHONNET_DEFINE_CONSTANTS

* PYTHONNET_PY3_VERSION, PYTHONNET_PY2_VERSION build related environment vars introduced.

* Small compile fixes.

* PYTHONNET_WIN_DEFINE_CONSTANTS and PYTHONNET_MONO_DEFINE_CONSTANTS introduced. + Fix for building mono versions under windows.

* Full featured xplat build.

* NetCoreApp 2.0 target added, compile issues fixed, CI system improved.

* .Net 45 TargetingPack System.XML.dll naming fix. (For xplat linux build).

* Setup.py --xplat option refactored. Travis-ci build matrix extended.

* AppVeyor matrix extended, xplat build added.

* appveyor.yml yaml syntax fix.

* NUnit dependency upgraded to 3.7. Changelog improved.

* EmbeddingTest fixes, and stubs.

* Fix for importing numpy and other python modules with native parts.

* Changelog improved.

* Build order improvement.

* NetCoreApp 2.0 fix. EmitCalli does not supports cdecl. Falling-back to a slow Marshal-based solution. + x86 fix.

* All finalizers are disabled until valid implementation. Helps to avoid non relevant CI build faults.

* Mono builds now can be build on Windows.
DEBUG;TRACE fix for the case VS + non empty PYTHONNET_DEFINE_CONSTANTS

* Python.Runtime.dll now targets NetStandard2.0 inplace of NetCoreApp 2.0

* Wrong NETSTANDARD/NETCOREAPP define constant change.

* Typo fix.