Always use 'bool' instead of 'boolean' after '@param' and '@return'

The former is by far the most common.

Skipped:
* resources/lib/jquery.ui/jquery.ui.datepicker.js
* resources/src/mediawiki.special/mediawiki.special.upload.js

Change-Id: I73c93797e745128ba703e4865080c36784caa474
Merge "Always use 'bool' instead of 'boolean' after '@param' and '@return'"