Extended KnockoutContext to be more flexible

I create a new constructor for CreateKnockoutContext extension to accept a string as a custon ViewModelName (needed to use multiple viewmodels in a same view like a partials...).

Also, I extended the Apply method to accept two news paramenters:

* wrapperId -> The element id to do the knockout binding (needed for multiple viewmodels in same mvc view). Empty by default for back compatibility.
* applyOnDocumentReady -> add the "$(document).ready" header to the autogenerated binding script. False by default for back compatibility.

All is tested and working in my development environment.

Regards!