Refactored the watch/unwatch icon for Vector.
- Changed from using an image to a div with background images.
- Redesigned the star icon, and implemented it as a sprite with unique watched/unwatch and normal/hover versions.
- Designed custom spinning star icon - used while waiting for server to respond.
- Added $wgVectorUseIconWatch setting to default preferences (defaults to false) and added support for enabling and disabling the feature.
- Got rid of old now unused icons.
- Changed ajaxwatch.js code to work with the div icon rather than the previous img setup.
- Regenerated RTL versions.