Updating the master version to 1.9.1pre.
Demos: Fixed titles.
Dialog: add required closing tag </button>. Fixes #8639 - jQuery 1.9.0 dialog on a XHTML page is broken if buttons are defined
Tabs: Handle extraneous list items when using ui-tabs-active to set the initially active tab. Fixes #8568 - jQuery ui tabs: wrong default active li if ul contains extraneous elements.
Remove use of $.browser; add $.ui.ie and $.ui.ie6 temporarily.
Sortable: Fix a bug of removing an item while iterating an array. Fixes #8571 - Out of range problem in when dragging a nested sortable.
Draggable: Fix a bug when dragging into nested sortables there are duplicated placeholders. Fixes #7777 - Draggable and Nested Sortables bug.
Sortable: Calculating item distance and direction using a more robust algorithm to better support sorting among nested sortables. Fixes #8572 - Wrong placeholder positions. Fixes #8573 - Can't drag an item out of an inner sortable. Fixes #8574 - Hard to put an item between two inner sortables.

Use the item which has the least distance between the mouse
pointer and one of its borders to rearrange, with direction being
determined by the nearest border.
Also we use this algorithm to rearrange even when currentContainer
is not changed to override the defective rearrangment in
_mouseDrag
Theme: Apply color to default link style in ui-state-hover. Fixes #7648 - Accordion Collapsed Color Issue.
Whitespace.
Datepicker demo: Fixed date range restriction when clearing dates. Fixes #5473 - Datepicker: Date range demo bug when clearing date.
Update AUTHORS.txt based on CLA responses.
Autocomplete: Set the top position of the menu so that the menu doesn't affect layout. Fixes #8656 - Initial position of autocomplete is incorrect.
Tabs: Use aria-controls instead of the anchor's href to match against location.hash. Fixes #8660 - Tabs: Set initial active tab from location hash for ajax tabs.
Merge branch 'master' into selectmenu
Tooltip: Change the default items selector to exclude disabled elements. Fixes #8661 - Tooltip doesn't hide on disabled anchor element [IE only].
Resizable: Use .insertAfter() instead of .after() to avoid recursively destroying. Fixes #8662 - Infinite loop - new to jQuery UI 1.9.0.
Spinner: Remove ui-state- classes from spinner, along with the background:none TR override. Fixes #8654 - Spinner background-color
Selectmenu: ARIA tweaks for keyboard events and closed menu operation
Dialog: Added mousedown event handler on dialog title to focus. Fixed #8063 - Dialog: Escape closes incorrect dialog.