Refine namespace exposure in core extension.

Privatize createPluginInstance and noConflicts.

Only use the jQuery sub-namespace when exporting.
Cleanup core extension.

Factor out _createPluginAPIAdditions.
Fix core extension plugin method not returning instance on re-invoke.
Add autoSelect and compactOptions...

This further lessens boilerplate across plugins.
Also update plugins.

Note that there's no conflict support. And that
compactOptions removes the original options
property.
Add initial core extension plugin tests...

Also add initial base test script for extending
QUnit. Just includes hasFunctions and
hasOwnProperties custom asserts for now.