Bugfix for pause/play using spacebar

When using the space bar to pause or play, it pauses then immediately resumes due to a bug in the key handler.
Quick cleanup of code to prevent file dragging

`e = e || event;` shouldn't be needed unless there's some webkit caveat I'm not aware of.
Be friendlier with owner of connectionCheckUrl

Changed to HEAD request since we're only checking connectivity.
Merge pull request #317 from download13/master

Bugfix for pause/play using spacebar