Fixes overflow issue when hidden content with the .screen-reader-text class is positioned hard right.
Merge pull request #492 from mor10/screen-reader-text_overflow

Fixes overflow issue on .screen-reader-text. See #484.
Move skip-to-content link to top to make it first focusable element for keyboard navigation.
Move skip-to-content link
Merge branch 'mor10-move_skip-to-content_link'
Remove leading space in stylesheet comment.
Pinking shears (remove trailing spaces) in two files.
_s: Revert f955fca630

The leading whitespace is needed to replace this `_s` instance with the theme name.
It's obviously a hack, since it also leaves the theme name with a leading white space, but short of adding a new replace logic for this specific line in `style.css`, it's the easiest way to achieve that.

See #304, where this was brought up before.
Merge with upstream/master.