bootstrap-select v1.6.3

Security release

Closes XSS hole in #735

New features:

• Added data-original-index (the rel attribute is now deprecated) #654
• Added ua_UA translation #742
• Added zh_TW translation #730
• Added translation callbacks in addition to strings #705

Fixes:

• #692
• #742
• #717
• #715
• #704
• #740

As always, you can compare this release with the previous one.