Support next version of Visual Studio
Don't query closed windows

SimpleTextView is an implementation of ITextView that implements several
COM interfaces.  In some cases it will throw from COM methods instead of
returning failed HRESULT values if it is closed.  Avoid this by short
circuiting earlier on closed views

closes #1352
Fix incremental search behavior

Start in 2012 or 2013 the IIncrementalSearch interface no longer
provides incremental search information.  Instead we have to screen
scrape and use reflection to determine if the IDE is currently searching
text.

closes #1347
Cleaned up the color definitions

All are now uniformly defined and properly disable the customization of
the foreground / background they don't support
Removed unnecessary colors
Merge remote-tracking branch 'origin/master' into fixes-colors