Use a different plist file for preview releases so early adopters can get updates before the rest of the users

Now that xcode 4.3 doesn't use /Developer and doesn't come with xcodebuild, remove the sudo ln -s /DeveloperX /Developer statements from the Makefile

Add EquivalenceClassSet. Simplify how tmux affinity works by using an equivalence class. Make window affinities go by window id instead of pane id. Add some rules to the makefile to facilitate avoiding xcode. Add session ID and expect it in %session-changed. Save window affinities when a tab is added or removed. Preserve affinities when attaching to a new session. Fix a bug where dragging a tab to make a split didn't work (safety valve triggered improperly).