Track open editors per document, and bring them to the forefront if they are opened when already open, closing #43
Fixed #33 and an error with opening files in the VPK from the project view.

More work on #36.  Now I need the editors to notify the document when stuff changes
Text editor can now save documents, Documents now close when all editors are closed.
Added syntax highlighting and theme support
Fix the checkboxes
Fixed a crash when rightclicking and updated KVLib and Sprache version to fix some KVLib bugs