Whitespace at end of lines

Leaving [trailing whitespaces at the end of lines](http://www.gnu.org/software/emacs/manual/html_node/emacs/Useless-Whitespace.html) makes it harder to participate.

It's not just against all coding styles, but most text editors fix such things automatically, creating a huge diff and making it difficult to commit.

I removed all trailing whitespaces across all source files.

I also rebuild `js` files with latest `coffee-script` from npm (just in case).