De-global padding of font-awesome icons.

Padding all font-awesome icons to the right on a site-wide basis means we
can't have unpadded icons anymore. We change this to a label class that has
the identical margin to the left.

Also, for some icons, we simply use a space, because the full spacing seems
excessive.
Merge pull request #52 from hlapp/icon-label-spacing

De-global padding of font-awesome icons.