Group, Select, Option, Outline and MenuSection widgets

Objective: Refactor menu widgets so that the majority of their code can be reused, and then add an outline widget which shares the same base classes.

ve.ui.Dialog.css
* Make dialog a fixed width and have a minimum and maximum height while always being centered in the window.
* Add style for the outline panel
* Add border below the title
* Move font-size adjustment to child elements to preserve layout scale

ve.ui.Inspector.css
* Make inspectors fade in when being opened (will happen after the size transition is complete)
* Add initial size for inspector to prevent the default size of the unfinished contents from making it too large while loading

ve.ui.Tool.css
* Update classes according to changes in labeled widgets

ve.ui.Widget.css
* Add display: block to widget labels to support use of autoEllipsis on them
* Update classes according to changes in labeled widgets
* Add styles for new select, option and outline item widgets
* Remove unused group and items classes for menu widgets (which are now subclasses of the select widget and no longer have grouping built-in)

ve.ui.Window.css.js
* Moved selection disabling rules up to the head to prevent selection drawing around the title

ve.ui.GroupWidget.js
* New widget that manages "items", allowing getting, adding, removing and clearing

ve.ui.MenuSectionItemWidget.js
* New widget that can be used inside a menu to create an unselectable, unhighlightable item that describes a section of the menu

ve.ui.OptionWidget.js
* New widget to be used with select widgets, provides select and highlight functionality

ve.ui.OutlineItemWidget.js
* New widget to be used with outline widgets, extends option and adds support for an icon to be rendered to the left of the label

ve.ui.OutlineWidget.js
* New widget that provides a vertically stacked list of mutually exclusive options, extends select

ve.ui.SelectWidget.js
* New widget that implements most of what menu once did, only now it also handles all the events for it's child elements internally

ve.ui.MetaDialog.js
* Hacked in support for an outline widget in the outline pane
* Added classes for styling purposes

ve.ui.FormatDropDownTool.js
* Modified call to menu item constructor as per changes therein
* Reorganized options config to make construction simpler
* Changed to setLabel after selecting the item to prevent the label from being changed to the wrong value as a side-effect of setting the item

ve.ui.DropDownTool.js
* Added $$ in config for menu widget - just in case later on we use a drop-down inside of a frame
* Using jQuery .text() method to propagate the selected item's text to the label rather than keeping around a plain text copy of the label in a property

ve.ui.Context.js
* Improve context/inspector behavior in regards to initial sizing

ve.ui.js
* Added context property to $$ returned by get$$ so it's easy to get the document object (for event binding) wherever you have a $$

ve.ui.Window.js
* Fixed incorrect case for boolean type in comment
* Added getFrame method

ve.ui.ButtonWidget.js
* Removed extra class being set on label

ve.ui.LabeledWidget.js
* Added class on label
* Added fitLabel method which uses autoEllipsis internally

ve.ui.MenuItemWidget.js
* Moved nearly all of the implementation to option so it could be reused

ve.ui.Menu.js
* Moved most of the implementation to select and group

ve.ui.MWLinkTargetInputWidget
* Prevent aborting and re-querying if the value hasn't actually changed
* Updated populateMenu method as per changes in menu class

*.php
* Added links to new files

Change-Id: I2271b5cc0554973b13cfbff94caf16901c02caa5