Added layouts and fixed up dialog styling issues

ve.ui.Dialog.css
* Fix issue where the use of margin auto on the outer dialog wrapper
  would expose parts of the underlying content - this is resolved by
  making the outer wrapper cover the whole screen and making the
  window frame use margin auto

ve.ui.Icons*.css
* Added missing settings icon rule

ve.ui.Layout.css
* Added styles for editor panel

ve.ui.Window.css
* Removed default height, setting it specifically in inspector now

ve.ui.EditorPanelLayout.js
* New layout, adds a title and icon above the content

ve.ui.TitledEditorLayout.js
* Similar to labeled widget, but for panels

ve.ui.MetaDialog.js
* Using settings icon now
* Switched to using a specific layout - still hard-coded for
  categories

ve.ui.Frame.js
* Modified style loader to guarantee order of style rules, no matter
  what order they load in

*.php
* Moved layouts to be included after widgets so they can use widgets
* Added links to new layouts

Change-Id: I7ff5f5f095460fd4f6cf841f4182bfb92bf034da
Merge "Added layouts and fixed up dialog styling issues"