* Fixed bug in sMethod in calc() (was using getValue, should have been setValue)
* Revised the sum() and avg() functions. Added the bind and selector arguments to both methods. This allows you to add automatically binding and a selector to place the newly calculated value. Either the bind or selector arguments can be an options object. Valid options are current:

- bind: the event to use for the bind() method
- selector: the selector (can be either a string, DOM element or jQuery object)
- oncalc: a callback method to run when the calculation occurs