Added the jQuery.ify method.
Extended the description of the jQuery.ify method.
Added a link to the jquery-utilities.md.
Added a link to jquery-utilities.md.
Added the jQuery.is function and its description.

I also removed some slightly redundant copy.
Removed an unnecessary JSLint global.
Updated the title.
Added Function.{execute, executeif} functions.
Merge branch 'master' of github.com:RobertoJ/js-utilities