Add support for GPL 2

Modify the text to include support for GPL 2
Add licenses text.
Merge pull request #464 from ericandrewlewis/master

Add dual-licensing support for GPL 2, which is incompatible with the Apache License
update license in js header
Add license text changes to README
Merge pull request #465 from ericandrewlewis/master

Update licenses text in README file
Update select2.js

Fixed line 2154 to allow Select2 work with multiple levels hireachal data.
Fixed anchor hrefs

Fixes #482: Mobile Safari issues
Merge pull request #487 from kevin-brown/master

Fixes #482: Mobile Safari issues
Merge pull request #485 from lisandropuzzolo/patch-1

Update select2.js
Rename spinner.gif to select2-spinner.gif to prevent collisions with very common filename.
Style consistency and proper intendation
Future friendly retina-mq

Using 'dpi' as a unit should be the way to go in the future
Merge pull request #502 from Inkdpixels/master

Style consistency for the stylesheet and a more future proof retina MQ
fixed dropdown positioning when select2 has margins. fixes #501
Merge pull request #495 from swhitt/master

Rename spinner.gif
Create locked items that can't be removed.

This patch creates multi select items that can't be removed.
Added .select2-locked
Goofed, changed disabled to locked.
fix typo in css