Upgraded to Marco Polo v1.5.1, which includes in important IE 7/8 bug fix.
Version 1.2.2.
Add jQuery.Deferred support to the formatting callbacks
and the onAdd event.

Allows async validating and formatting of input values
updating readme to require jquery 1.5+ for deferred support
add an onFormat rejection handler
Merge pull request #9 from rauhryan/deferred_support

Deferred support
Cleaned up new deferred object code. Removed 'onFormattingRejected' callback as it's too specific for an optional feature.
Added link to 'Showing a Busy Indicator' in the README.
Added info to the README about the use of Deferred objects in select callbacks. Updated the requirements to specify the correct version of Marco Polo.
Updated copyright year.
Updated jQuery UI Widget to version 1.8.21.
Added ARIA support.
Updated Marco Polo to v1.6.0.
Small fixes brought to light by JSHint.
Version 1.3.0.
Upgraded to Marco Polo v1.7.1.
If Marco Polo is in use, returning 'false' in 'onSelect' will now prevent 'onAdd' from even being fired.
Pasted input is now split by all of the applicable character separators and the resulting values are added. Initial values are now split by all character separators as well, not just the first.
Pasted values are only added if arbitrary values are allowed ('required' is 'false').
Added missing semi-colon.