Get ready to Diverge

• cleans up some tech debt where UI image scrubbing and backstop init command were originally implemented as hacks.
• Add the backstop remote command. Running backstop remote [--config=<path>] in a separate terminal launches a simple web server such that reports can be shared live with all your buddies. The backstop openReport command now checks for a server running on localhost and will automatically choose the web hosted version if found. Requires that bitmap_reference, bitmap_test, html_report are all accessible to your current working directory.
• added "Diverged" image diff library -- in development here... https://github.com/garris/diverged -- so we can eventually have our diffs be more awesomer.