Moved some things to local bashrc
Made tab-completion in bash F*CKING AWESOME (a little better)

I've been annoyed several times when there's a new command added to a
command-line tool that I use which messes with my tab-completion is such
a way that what I normally write before hitting <tab> is no longer
enough because there's too commands that starts like that. This maps TAB
to menu-complete which completes the first command and shows all
available letting me hit tab again if I don't want the first match.
Adds vim-like mappings for page-up/down