Move edit tab generation into PHP and make it more configurable

* Generate the edit tabs and the section edit links in PHP, with a
  fallback in JS for cases where we don't have them yet due to
  caching. But only change things if VE is enabled, and have the JS
  correct the state if the wrong cached HTML comes through.
* Make the order of the tabs/links and the messages to use as captions
  configurable
* Make the edit tabs and section edit links always be present in the
  page (regardless of namespace, user prefs, etc.) but be hidden and
  have JS unhide them (using html.ve-available) if appropriate
* Add appendix messages so we can do a superscript "beta" even in places
  where we can't use HTML in the message

VisualEditor.php:
* Add new hook registrations
* Remove edit link caption messages from the init init module because
  they're now added dynamically in VisualEditor.hooks.php
* Add a noscript CSS module so we can hide some things in JS-less
  environments
* Remove $wgVisualEditorTabLayout and replace it with
  $wgVisualEditorPosition
* Add config vars for link captions, with null causing us to use
  the default caption
* Add config vars for link caption appendices. Too many config vars
  but we'll clean that up later

VisualEditor.hooks.php:
* Dynamically add tab messages to the init init module
* Remove unused globals in onBeforePageDisplay()
* Add noscript CSS module
* Add a SkinTemplateNavigation hook that changes and reorders the edit
  tabs as appropriate
* Add a DoEditSectionLink hook that overwrites the edit section links
* Export the new config variables to JS

VisualEditor.i18n.php:
* Add beta appendix message
* Add a message for the default VE edit section link

ve.init.mw.ViewPageTarget.init.css:
* Remove the animation on the edit section links
* Darken the color of the brackets and the pipe from #ccc to #555
* Style the beta message to be superscript-like (but not real <sup> to
  avoid moving the baseline)

ve.init.mw.ViewPageTarget.noscript.css:
* Hide the VE edit tab, the pipe and the VE edit section link initally
  unless and until JS unhides

ve.init.mw.ViewPageTarget.init.js:
* Toggle .ve-not-available / .ve-available
* Edit tabs
** Only generate the the edit tabs if they're not already there from PHP
** Rewrite the edit tab generation to mirror what's being done in PHP
* Section edit links
** Same as for edit tabs
** Also add mw-visualeditor-expanded to pad the brackets

ve.init.mw.ViewPageTarget.js:
* #ca-ve-edit is now always the VE tab (and #ca-edit always the
  edit source tab) so update the .selected behavior accordingly

Change-Id: Idcb15faea7fabe5fe7578b1508079969b27d2469