Replaced Powerline with Airline:
* Airline is faster, neater and written in pure vimscript.
* Does not require additional packages/Python.
* A vimscript version that is being maintained (not the old repo)
* Supports a wide array of plugins such as vim-bufferline and tagbar
* Does not require a patched font for prettyness, only unicode.
* Easily customizable and themeable.
* Removed the old fonts used for Powerline.