fixed replace event bugs in BBGun

replaced some bugs with replacing nodes,
and firing the relevant events, in BBGun.

Also streamlined the way arguments are passed,
and this means that in some cases, some overhead
will be removed.
fixed bugs with replacing double operators, with a double operator.
fixed BB and BBGun event bugs

* Fixed bugs with handling browser specific prefixes.
* in BBGun, all event names now lowercase, and browser prefixes removed
* bb now handles 'transitionend' events correctly (using a webkit
prefix).
* 'remove' and 'beforeRemove' events added to BBGun
* replace method bug fixes, for BBGun
fixed more bugs from the BBGun move over

* auto-selecting of the next node, when a node is deleted, is now
handled correctly
* default insert behaviour has changed
* DoubleOp insertion bugs solved