Update our sample code (#224)

Removed a bunch of old examples that are not so useful, and tidied up the remaining ones:

* Removed unused bytes and labels.
* Updated to ensure that several reported upon the correct drive-letter.
* Little tweaks to make behaviour better.
   * e.g. Testing that creating a file worked, or ensuring a file exists before trying to delete it.

This closes #222.

Improve how changing the CCP at run-time is handled. (#204)

Much like recent changes this pull-request improves the handling
of changing the CCP at runtime:

* Show output in a way that is testable.
* Add the tests.
* Recognize a "no-change change".
* Remove needless quotes.

Add timeout flag, for testing. (#188)

* Add timeout flag, for testing.

This will now be used for all test-cases, and will cap runs at two
minutes.  This might be useful to others, but for the moment I struggle
to think of a good purpose!

This closes #186.

* Setup a default context for when nothing was specified

Improved test coverage percentage

Merge pull request #160 from skx/65-input

Avoid the unnecessary invokation of STTY

Better handling for file-sizes

Remove mention of 'real' programs, since lots of stuff works now.

Merge branch '127-fcb-state'

Added DirectScreenFunctions, which is used by Turbo Pascal

Merge pull request #105 from skx/104-virtual

Implement a naive virtual filesystem