Update coro() method to return `create` and `wrap` values.

[johnd0e]

This is commit from far-support branch: https://github.com/pkulchenko/MobDebug/commit/0801f1847477dc1b01f789bb99506019ac31f150

Discussed here: http://forum.farmanager.com/viewtopic.php?p=116873#p116873

Edit The idea behind current coro is great: to hide all tricky doings into 1 high level function. Unfortunately, it's not bullet proof enough, and to handle possible issues one must clearly understand what exactly is happening inside (and due to lack of documentation it's necessary to inspect mobdebug source code).

Thus the idea of 'highlevelness' of this function gets completely destroyed. So I propose to make things a level lower, but a lot clearer way.