Split ve.ui.Toolbar and ve.ui.SurfaceToolbar

Objective:

* Make it possible to make a toolbar without a surface

Changes:

*.php
* Links to new file

ve.ui.Toolbar.js, ve.ui.SurfaceToolbar.js
* Split toolbar into generic and surface specific classes

*.js
* Update symbol names

Change-Id: Ice063a2fb67b5ce5155cdc96a0d47af49eee48cb
Merge "Split ve.ui.Toolbar and ve.ui.SurfaceToolbar"