add default to scss variables

Doing so allows one to override default variables when writing custom SASS that imports Ratchet's SASS.
Use `textContent` when `innerText` is not available.

Firefox does not implement `innerText` so this led to another `TypeError`.
updating the header on all the js lib files
Merge pull request #526 from twbs/mit

Consistent MIT license header
header-gradient
line up rules
Merge pull request #527 from twbs/header-gradient

Making sure our header gradient works everywhere...
don't make room for cheverons
make input-rows have the same height as inputs.
fix the positioning of the jump menu
fix the actual menu positioning
widen the home button and ad.
making sure the text remains gray when active
run grunt
conflicts
running grunt
Merge pull request #528 from twbs/and-badge

Fix the padding on table-views in the android theme
Merge branch 'master' into input-height
run grunt
Merge pull request #529 from twbs/input-height

Make inputs and input-rows a consistent height