Add to ProjectFile Unit Tests

Add test cases, implement resharper suggestions and fix the assert
statements, since the arguments where given wrongly.
Add String Test, Rename Tests

Tests now have their targeted class name prepended to the front of the
test name so it can be more easily deduced from the test browser.
Merge branch 'master' of github.com:IMDC/LiveDescribe-Desktop into valdev
Rename InfoTab ViewModel Properties
Refactor Play_Tick handler

Separate logic into other methods and classes
Move Play and Stop methods out of Description
Fix Description Selection on Play

Returned to what it was before the DescriptionPlayer class was added.
Merge branch 'master' of github.com:IMDC/LiveDescribe-Desktop into valdev
renamed binding property
refactored the marker into it's own view