Add airline plugin for Vim

Ad the configs into vimrc for airline as well as the modified Ubuntu
font to make it work. This was taken from
https://github.com/Lokaltog/powerline-fonts
Add tmuxline and configure tmux theme

Use tmuxline to generate a pretty nice tmux status line. Disabling
airline tmux plugin to keep the theme as-is. Going to keep the Vim
plugin around for a while but might get rid of it later.
Update Vim bundles