Removes the airline symbol settings.

Now I use a patched font (Lokaltog/powerline-fonts).^

Signed-off-by: Markus Hubig <mhubig@gmail.com>
Fixes a bug where airline is only showed on splits.

Signed-off-by: Markus Hubig <mhubig@gmail.com>
This was stupid!

Signed-off-by: Markus Hubig <mhubig@gmail.com>
Switches to the very nice Source Code Pro font.

This is actually the patched one from here:

    https://github.com/Lokaltog/powerline-fonts

Signed-off-by: Markus Hubig <mhubig@gmail.com>