Results sorting option. Refs #95
update `this.context` with data context on query calls
Firefox Tab and Enter keys issue.

When item is selected by enter, the list is reopened.
Also pressing tab on focused element with drop list cause immediate reopening with empty search result list.
Triggers change when value is set programaticaly.

``` js
$('#select').select2().
    on('change', function () {
        alert('change');
    }).
    val(['foo']);
```

Now shows an alert window.
Merge pull request #619 from cup-of-giraf/master

Trigger an event on value programatically change
Update select2.js

Adding case to fix placeholder not being displayed when element not visible.
Merge pull request #632 from crueber/patch-1

Update select2.js
Fixes >1 multi-select dropdown being open at the same time

Bug was reproduced on latest FF/Chrome/Safari, but IE exibits correct
behavior with or without the fix.

See: http://jsfiddle.net/tmD7c/2/
Merge pull request #635 from t0m/multi-select-dropdown

Fix for more than one multi-select being open at the same time
Added the option to select highlighted upon blur, false by default. Original functionality is maintained by default.
Update select2.js

jQuery("input#someId").attr("tabIndex") don't work well in new jQuery 1.8+.
When you try this on field  that don't have tabIndex attr you get undefined 
(but document.getElementById("someId").tabIndex returns '0').
This is why Select2 element onBlur stay whit attr tabindex='-1' 
and you can't navigate form with 'tab' key.
This simple ' || 0' fix this bug.
Merge pull request #644 from kfiku/patch-1

Update select2.js
Be able to limit each input to a maximum length
Merge pull request #594 from omab/master

Results sorting on populateResults function
Merge pull request #652 from tispratik/master

Be able to limit each input to a maximum length
add [option disabled='disabled'] support. fixes #480 fixes #157
Make the escapeMarkup function escape html tags and some other characters and apply it to usefull places
Merge pull request #643 from akinnee/master

Added an option: select highlighted option on blur, "selectOnBlur: false"
Allow to pass a callback as ajax.url
Merge pull request #692 from 4sh/master

Allow to pass a callback as ajax.url configuration parameter