Reference dialog

Objective:

Add a basic (empty) dialog for mediawiki references. Editor to follow.

Changes:

*.php
* Added file links and messages

ve.ui.MWMetaDialog.js
* Moved initialize method to the top (for consistent ordering)

ve.ui.MWReferenceDialog.js
* New class, basic empty dialog for references

ve.ui.LinkInspector.js, ve.ui.MWLinkInspector.js, ve.ui.MediaButtonTool.js
* Cleanup documentation
* Whitespace

icons.ai, reference.png, reference.svg
* Switch to reference icon being 3 books on a shelf

ve.ui.MWReferenceButtonTool.js
* New class, basic dialog button for references

Change-Id: Ia4e30e9239fa1e3b28c0a1ef1ca0a6515a8103ef
Merge "Reference dialog"