Cleanup JS

* Add missing spaces after 'function'
* Remove underscores from identifiers
* Don't use typeof for undefined with local variables and object properties
* API ok/err is deprecated since MediaWiki 1.20 (< 1.22-alpha), use .done and .fail

Change-Id: I5ca3403ee263a0c3e6709618e48e896340952337
Merge "Cleanup JS"