Copy several util methods required to convert xpath.coffee, util.coffee and eventually range.coffee into javascirpt. This first step is to just convert the modules straight over and add basic unit tests for them which previously were missing.

A few changes have been made:

- findChild is exposed in part so it can be moved to this module and also be unit tested easily.
- simpleXPathJQuery- will eventually go away, but as a first pass, its being ported
- jquery is kept in this context, but eventually all methods that expect a jquery object will be converted over to pure js.
- typechecking is not complete