#385, #384: titles for options, supporting dataprovider; dataprovider with preselected options.

Allow options to be defined by data attributes.

#305, #302. Added enableClickableOptGroups option.

Only deploy the necessary files with Bower.

#377. Allow enter in filter.

#365. Additional option for selectAll.

Factorise some code too

Add ability to handle the "caption" property from the dataprovider() to display a title on hover of each option label

Update doc

Just set the 'selected' property to true on the data item
Works also for optgroup's options.

Also use jQuery tag constructor and attribute setter to avoid HTML filtering issues

Target main button for updates more explicitly.

Allow onChange to trigger when calling `select` or `deselect` with one value.

When updating the button text/title, target only the main button. This allows for additional buttons in templates to remain unaffected. For example, extra buttons in the filter template.

Knockout.js Binding: Fixing the initialization of the selected items in the multi-select