Added underlining for abbreviations.
Load fonts using HTTPS if on HTTPS.
Element spacing is now relative to its font size.

I didn't add any new overrides for basscss.css definitions, just changed
the existing ones. All changes made are calculated to have no visible
effect at the current font sizes.
Fixed two font sizes not given in rem units.
More consistent header sizing.
Add optional animation to config for pretty animations.
Apply animation to the body.
Modify transition CSS, closes #69.
Add animate documentation, closes #72.
Convert css to scss with compression.
Add .sass-cache to .gitignore.