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

Update bootstrap-multiselect.js

Little correction to dataprovider.

Fix #322

Fixing the initialization of the selected items in the multi-select for Knockout.js binding integration.  Currently a persisted binding value isn't being initialized correctly when using KO.  Instead the selectedOptions are only being set on during the update binding function or when the observableArray is changed.  With this fix, if the observableArray has initial values, they are selected as necessary.s

There is a little correction to the method dataprovider, the parameters for the callback function are index, value.  Probably the problem is that in the forEach method of an array this two parameters are inverted.

Conflicts:
	index-2-3.html
	index.html
	js/bootstrap-multiselect.js

** fix for #282: prevent crash when trying to select non-existant value **

prevent the "select all" from being created twice

Option groups support for the dataprovider method

Signed-off-by: Tyf0x <Tyf0x@users.noreply.github.com>

** Keyboard navigation fix: disabled elements are no longer selectable *...

** Removed the mirroring on the "Select All" option. **

Signed-off-by: Tyf0x <Tyf0x@users.noreply.github.com>

Signed-off-by: Tyf0x <Tyf0x@users.noreply.github.com>

Moving down the onChange callback

** Performance improvement ** - based on thorst #268 contribution.

adding namespace to fix keydown event.