saving small changes.
Implemented a "deep copy" (via constructors) for TaggedDocument.
Untested. May be buggy.
- New shortcuts have been added for "save", "save as", "undo", and
"redo"

-New Undo and Redo pull down menu options, code structure's in place but
not complete yet.

-The OS X menu look and feel is finally done correctly (no longer
relying on a deprecated library)
Pre merge commit
Merge remote-tracking branch 'origin/Andrew_McDonald' into Marc_Anonymouth
-Edit undo and edit redo are complete.