- Add new Factory constructor to detect when a module in the cache is ready to have its factory executed.
- Abstract methods to get modules out of the cache and ensure that cached resources have had their factories executed.
- Ensure that `define()` calls are performed in the next turn, but always before other next-turn tasks.
- Fix curl/tdd/undefine so that it also removes from url cache.
- Always early export if the module uses `exports`, `module`, or `require` since it is safe to do so in all cases now.
- Restrict cases for urlCache to just bundling strategies.  Other cases (wherein devs map multiple paths to the same location) will load the modules more than once.
- Add and/or fix tests!

…eting it *as* a factory when it is a function.

Fixes #268.