Objectives:
* Use a class for toolbar groups to add more functionality later
* Rename addTools method to setup
Changes:
*.php
* Add link to new file
* Move ui element classes up for more general use
ve.init.mw.ViewPageTarget.js, ve.init.sa.Target.js, ve.ui.Context.js,
ve.ui.SurfaceWidget.js
* Update use of addTools method
ve.ui.Tool.css, ve.ui.Toolbar.css
* Move styles between sheets
ve.ui.Toolbar.js
* Rename addTools to setup
* Use ve.ui.ToolGroup objects when building tools
ve.ui.ToolGroup.js
* New class, encapsulates tools
Change-Id: Ic3a643634a80a8ac7d6f6f47f031d001c7efaee7
