More fixes to make commercial X-browser

 * stop using `Array`'s some (use `lodash`'s)
 * don't use `bonzo`'s `css` method if `getComputedStyle` doesn't exist
 * change the way we get the breakpoint in JS; IE can't get the content data, so use `font-family` to store the breakpoint too
gonna update in `guss-typography`