Make `tmux` configuration emacs friendly

This is the sweet spot, right here.
Add quick vimscript function to add cabal versions

This is a quick-and-dirty script to insert haskell dependency versions
into the current buffer.
Update the `tmux.conf` file

Adds bindings to resize tmux panes to a percentage of the screen space
and set the `escape-time` to 0.
Add battery status to the tmux status bar

Need to specify dependencies:
- `battery`
- `spark`