Fix: Cabin LESS stuff

• Whoops.  Forgot to add all the necessary LESS stuff to the `cabin-*.less` and `cabin-condensed-*.less` files:
	◦ `@font-weight_*` vars.
	◦ `@font-style_*` vars, for the ones with italic variants.
	◦ `.font-face_*()` mixins.
	◦ `.font_*(…)` mixins.
Fix: Duplicate `@font-face`s

• Fix for duplicate `@font-face`s appearing in the generated CSS after each use accomplished by:
	◦ Turning each `.font-face_*()` mixin into a non-parametric mixin (just a CSS class).
	◦ Changed each `.font-face_*()` mixin usage into an `&:extend(.font-face_*)`.  This works by gluing the `&` part's selector (the client `.font_*()` mixin, resolving to the using selector) onto the selector list for the `.font-face_*` mixin.
	» Somehow, the `.font-face_*` mixin disappears, and the `@font-face` appears only once.  I don't actually know how this works.  Magicks!
Just a few more fonts

• Added Calligraffitti, Fredericka the Great, and Megrim in the same manner as the others.
	» I guess I really love fonts?
	» No `-regular` suffixes here since they're all single-variant fonts.