Add ability to search all files in the project

Adds a "Find in Project" option to the "Project" menu and a "search" function to the ProjectManager.  Regular expression and multiline queries are supported.  Clicking a result will open the file (if not open already) and move the editor's cursor to the appropriate line and column.  I have plans to make this a combination "Find / Replace in Project".  Let me know if you have any questions.
I'm not wild about attaching JS data to DOM elements, since it's a memory leak waiting to happen. I also don't see any particularly good reason to do so, since you never use it outside of this closure.