Add new option to cache style and $truncateWorker when working with multiple elements.

If you have a bunch of elements with the same style and you run truncate it can be very slow (was seeing up to 2 second browser freezes with 50 elements).  Caching the style and $truncateWorker from outside of the loop can reduce this to 10ms (element creation and is very slow in jQuery).  Obviously only useful if your elements share the same style.