dispatch.vim 1.1

* Force quickfix window to very bottom.
* Fire a QuickFixCmdPost event after loading results.
* Set xterm title with screen and tmux.
* Tweak screen adapter for wider version and distribution support.
* Default :Start to b:start.
* Ensure identical environment vars (fixing in particular RVM support).
* Allow greater compiler detection control with g:dispatch_compilers.
* Enhance and fix bugs in compiler detection.
* Don't launch iTerm if not already running.
* Numerous small bug fixes.