renaming overload to override. props emiluzelac.
also changing overload to override in comments.php & archive.php
Merge pull request #290 from BFTrick/rename-overload

Use 'override' instead of 'overload' to avoid confusion with overloading properties and methods in PHP.
_s: Update selectors to reflect the changes in 810e499. Fixes #288.
Renamed (most, hopefully) of _s occurences