Update select2.js

bugfix: .select2("data", null) for remote datasource causes an error "ReferenceError: e is not defined"
Floor the searchWidth calculation due to inconsistencies between fractional pixel handling in different browsers
Update select2_locale_ar.js

Translate in the of 1 or 2 or more than 2 because not the same in Arabic.
Remove -ms-linear-gradient that was only used by IE 10 preview releases.
Remove -o-linear-gradient used by Opera 11.1 - 12.0. These versions are now very rarely used.
Remove -khtml-user-select. It's not supported by KHTML anyways and their marketshare is incredibly minor.
Remove duplicate property.
Fix the focus when list is closed on the mouse click event
Clicking outside of dropdown removes select2-container-active class.

Closes #1661.
Merge pull request #1667 from duckinator/master

Clicking outside of dropdown should remove select2-container-active class.
Merge pull request #1628 from realityking/css

Cleanup CSS
Revert "Fixed Tab key not respecting opts.selectOnBlur" breaks tab key. fixes #1646.

This reverts commit 6eb74930d58f7265839ecf256eedc72ef29d068b.
Added `select2-clearing` event
that allows clearing selection to be canceled.
Merge pull request #1675 from duncansmart/clearing-event

Added `select2-clearing` event
Remove duplicated options from multi-valued select boxes.
Merge pull request #1678 from jdecuyper/feature-remove-duplicated-option

Remove duplicated options from multi-valued select boxes.
Avoid locked options to be selected and deleted.
Merge pull request #1684 from jdecuyper/feature-avoid-removal-of-locked-options

Avoid locked options to be selected and deleted.
Merge pull request #1211 from jhinch/pixel-rounding-problems

Search width inconsistencies in different browsers due to fractional pixels
remove trailing comma. fixes #1633