Add NS as a source language in the (Emulab version of the) Portal.

In order to transition users from the Classic interface to the Portal interface, we had the idea that we should add NS as a source language on the Create Profile page. The backend would run the NS parser and convert the results to an rspec instead of an emulab virtual topology. Not all NS syntax would be supported, this was also discussed at the meeting (see #38 (closed)).

@ricci, @eeide, @hibler, and @johnsond were present.

Thoughts and comments welcome!