Merge pull request #87 from nexces/master

Bootstrap 2.3.2 styling.
Fixed #82. Added bet js and demo page. The "new" multiselect will be more structured but hopefully offering the same possiblities with better performance.
Fixed #82. Added beta js and demo html. The "new" multiselect will be more structured but hopefully offering the same possibilities with better performance.
Fixed #92.

See #92.
Altered filtering behavior

Filtering can be now done on option lables or values or both.
Configurable via: 'filterBehavior' option
Possible values are:
* 'text' (default) - uses only label text for filtering
* 'value' - uses only option value for filtering
* 'both' - uses label text and option value