Replace getWikipageUrl with mw.util.wikiGetlink
Rewrite options handling and settings form layout width

* Removed unused function isEmpty.
* Replace getParamValue with mw.util.getParamValue.
* Fix duplicate call to krRTRC_GetRCOptions (now readSettingsForm).
* Remove margin/padding reset that caused checkboxes and select
  to align slightly off.

Also:
* Cleaned up layout for rtrc footer,
  removed need for "inside" wrapper.
Use native scrollIntoView instead of location.hash

Keeps the url cleaner and prevents addition entry from being
created in the browser history.
Add mediawiki.Uri to dependencies

The mw.Uri constructor is used in 2 places.