simpler ctags config

Now using tmm1/ripper-tags for Ruby and mislav/cstags for CoffeeScript
stop using oh-my-zsh termsupport

Throws warnings in some command substitution expressions.
Plus I don't care much about terminal title anyway.
Speed up prompt: remove Ruby version & git dirty info

Git status was the slowest: more than 200ms on large repos. rbenv
lookups were reasonably fast, but not crucial to have. Looking up the
git branch is silly fast and that info is useful to me, so it stays.
`tmux-session restore` doesn't choke on non-existing dirs
gif2mov for all your Keynote 6 needs