1.11 upgrade guide

[jzaefferer]

We need to start working on the upgrade guide asap. Let's list topics in here, then do a PR.

See http://jqueryui.com/changelog/1.11.0-beta.2/ Reference for a previous guide: http://jqueryui.com/upgrade-guide/1.10/

All:

• Renamed all files, removing the "jquery.ui." prefix
• Updated quick and custom download zip file
• AMD and Bower support, see learn articles

Accordion:

• Remove deprecated content property in create event

Core:

• Core: Deprecate .focus( n )
• Core: Deprecated .zIndex()
• Core: Removed $.ui.hasScroll()
• Core: Removed $.ui.keyCode.NUMPAD_*.

Dialog:

• Dialog: Removed deprecated position handling
• Dialog: Switch back to shuffling z-index, but only look at .ui-front siblings.

Effects:

• Effect: Give puff-effect and size-effect its own files. Previously, they were into scale-effect file.

Menu:

• Menu: Add items option for better definition of menu items in non parent-child structures
• Menu: Remove the requirement to use anchors in menu items (no ticket reference in beta.2 changelog, create a retro ticket)
• Menu: Simplify styling. Remove rounded corners, reduce spacing.

Slider:

• Slider & Interactions: Add Windows 8 touch support
• Slider: Switch handles from to

Spinner:

• Spinner: Add isValid method

Widget:

• Widget Bridge: Make the _init method optional.
• Widget Factory: Make $.widget return the constructor.
• Widget: Implement instance method on the bridge to return widget instance
• Widget: Make .enable() and .disable() act via ._setOptions() instead of ._setOption()
• Widget: Only remove hover and focus classes when disabling, not enabling.
• Widget: Stop setting ui-state-disabled and aria by default on setting disabled option
• Widget: Support events with dashes and colons

I've added a list above based on entries in the changelog that didn't look like bug fixes.