Fixed a crash relating to opening the same document twice.

More cleanup and working on stuff.
Added right-click context menus to the ProjectTreeView and VPKTreeView.
Added TODOs to the TreeListCommands
Added 'Open' command to the context menu.  Working on a Folder browser for the dota 2 directory setting
fixed the settings so the folder explorer now works
Added KVLib to the dependencies
Implemented KVDocument, a way to load KeyValue documents
Added Localize() calls for all user facing strings for when we get around to localizing Worldsmith
Open KeyValueDocuments in the KeyValue editor and enabled the Right-Click menu to open the KeyValueEditor
Better handling of 'View Source' option
KeyValue Editor displays properties, but is kinda buggy
Remove the crappy KeyValue editor and do a tree list instead
Execute the Open command when double clicking on a file in the project explorer.
Increase the default width of the columns
Annotate the Key-Value type, and set the selected Key-Value as the active context.
Fix validation a little bit for dota 2 directory strings.

Just bringing this change into the right branch.
Specified the context in which the commands should be selected.
Merge pull request #1 from RoyAwesome/master

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