Fixed chained array result

Added modifiers and path chaining

A modifier is a path component that performs custom processing on
the json.

Multiple paths can be "chained" together using the pipe character.
This is useful for getting results from a modified query.

See the README file for more information.

Valid json optimization

Added ~20% performance boost be removing extra allocation when
Valid() is called with a json string.

Added GopherJS support

Merge pull request tidwall#98 from thirstycoda/master

Added not like operator support to query

Fix leftover array and map values

fixes tidwall#81

Add appengine support

Fix false validation

closes tidwall#73

Merge pull request tidwall#66 from Hexilee/master

Result.Bool() can parse 'false' as false

array query mismatch, fixes tidwall#58