Merge pull request #1 from rstudio/master

Syncing my fork...
Add the "Clear Recent Projects" menu item to the popup
Changed the menu label such that it is more relevant for the projects popup menu
Added the callback to actually clear the recent projects from the popup menu
Shift the "Close Project" menu item to the near the top so the bottom of the popup is not so cluttered...
Change the label of the clear projects menu item to be shorter
Just another small editorial tweak
File search: match on subsequence rather than start of name
Order search results by score
Refactor; wire up R source object machinery as well
Better scoring
Tweak scoring a bit (don't give bonus on '.' for file extension)
Depending on 'j' unnecessary as all scores calc'ed on same query
Penalize less interesting files
More work on server side to return highest scoring matches
Ensure 'try' is called from base package
Escape library names on package load
Check for '.rstudio-protocol' file before attempting to check namespace
Allow 'debugSource' to be executed in user-specified environment
Use 'local' argument, as per 'source'