Merge pull request #122 from caseyjhol/master

Add icons to options (data-icon)
Fix multiple (selected == 0 is correct)
Merge pull request #124 from vsn4ik/fix_multiple

Fix multiple
Fix #125
Fix #125
#125

Remove the tabindex on the button when a disabled select is enabled.
#125
Fix #121 (add data-hidden attribute)
Fix #121 (add data-hidden attribute)
removed href
Update bootstrap-select.js
Fix #69 and other small bugs