Clarify and document required/supported libraries

at least until #490 is completed.

consumers can decide whether or not to include it in their app depending on the version of jquery they are using

Also, use a greater than instead of a tilde for defining the jquery requirement.
This doesn't seem correct. We need to have the `jquery.browser` requirement somewhere in this file so that [grunt-bower-install-simple](https://github.com/rse/grunt-bower-install-simple) knows to install it and put it in the `lib` folder. Am I going crazy?