don't clobber $

jQuerify is only checking for `window.jQuery` and not running in `noConflict` mode. Using jquerify on any page that defines `window.$` breaks the page.

Trigger noConflict mode to restore `window.$`. Subsequently, to use jQuery one must use `jQuery` not `$`.
don't lie about when jQuery is loaded
only put jQuery into noConflict mode if $ was already in use
update readme
Merge branch 'jquerify-noconflict' of https://github.com/jasonkarns/devtools-snippets
whitespace
rake build