Hygiene: Some clean-up of the Minerva skin code

* Fix some indentation in MinervaTemplate.php
* Remove redundant bottomscripts setter. This is set by the
  parent, and we don't have any child versions in Minerva.
* Organize code with better whitespace and comments.

Change-Id: Ice05f110cfe91f1d2ce67c5cc40d3168df95d6c2
Merge "Hygiene: Some clean-up of the Minerva skin code"