expandregion vim plugin; lots of new vim key mappings
updated ssl cert fingerprint for imap server
neat trick for platform-specific behaviour for tmux
improve behaviour with space key as leader ...

... due to shorter key timeouts. Without this setting, vim would wait too long
on each pressing of space key
added convenience script for updating a fork to latest master from upstream
improved ack usage
adding lightline vim plugin; overhaul and restructure of vimrc