Changes for API v2

These are the changes for API v2:

* Posting of artifactgroups has been removed
* Notes on projects have been removed
* Reagent endpoint has been removed
* Permissions endpoint has been removed

Basically I just refactored the namespace map dictionary adding missing endpoints and removing old ones. I also removed the *notes* attribute from project, and fixed the corresponding example.

@pekrau, would be nice if you can take a look at this pull request before it is merged :-)

Tack!