Bootstrap 3.0 support

* new class: Bootstrap.Affix and the associated behavior
* Popovers (and tooltips if you like) can now have their 'trigger' option set to 'click' which allows you to show them on click instead of mouseover if you like.
* Delegator.BS.ShowPopup now allows you to just use a #href reference to the id of the popup to show.
* Dropdown now allows for you to have its behavior on the Dropdown itself instead of a container.
* Bootstrap.Popup now expects that the layout matches Bootstrap 3. *This is a breaking change* but compatibility has been left in place for Bootstrap 2. For this to work, you must set `Bootstrap.version = 2` in your code.
* Bootstrap.Popover's offset defaults are now zero unless `Bootstrap.version` == 2