CodeSearch-Plugin M3

I've fixed a bunch of bugs in the CodeSearch-Plugin:

the plugin won't reopen the same file multiple times

the plugin allows you to open local project files from the search results (via a right click)

the plugin now works if you have multiple projects open in IntelliJ

there's now a dialog to tweak the search

But there's still a few important tasks left to do:

manage the search regular expression more carefully

preflight file type selection for Google Code Search

preflight argument selection for commandline search

I gotta get this thing working great soon, since it's already featured on the API page!