Don't add the GNU package repo

* should already be there
Disable mmm-mode in favor of web-mode

* also enable emmet-mode

I find this web-mode a better fit to my workflow
Disable electric pair mode

* not sold on its usability yet; currently more of a distraction
Add `{un}tabify-buffer` convenience functions

* sometimes buffer bludgeoning tools are handy
Update reference to planet theme
Add support for coffee-mode

* includes hacky way of getting tabs instead of spaces... I had no
  choice, work standards :(
dired: whitespace removal convenience functions

* for single and multiple files