Minor edits, obsessing over whitespace

A minor edit to the JavaScript for updating the character count residing at
js/ext.CommunityTwitter.updatecount.js that gets to the point and attaches the updateCount function
to the onkeyup event without function declaring/calling convoluting. This commit also adds more whitespace
in and also includes some comments to aid in reading the JavaScript function. Additionally,
a braceless if-statement in CommunityTwitter.php was rewritten with braces for safety.
Furthermore, whitespace has been converted to tabs where appropriate in the extension and
extraneous spaces have been removed. Tldr: To-may-to, to-mah-to.

Change-Id: I8b51ba617508d4303cfa12d0d5e8a1ae86144d16