Expand Network Import format

[dotasek]

POST /v1/networks does not support the following formats:

• BioPAX

• XGMML

• CSV/TSV/TXT

• Excel

• GML

• GPML

• GEXF

• GraphML

• NNF

• OBO

• PSI-MI 1

• PSI-MI 2.5

• SBML

• SIF

• Empty - should generate an empty network

Note that some of these (I'm looking at TSV/CSV) require unique parameters to function, which the current v1 endpoint does not support.

[dotasek]

This is related to #66 in that we're trying to do a lot of work with a file, stream, or url, AND support the existing JSON formats from the RESTful endpoints.

Getting this to make sense might be a struggle.

[dotasek]

This, along with #66, could be taken care of by using some of the code used in the drag and drop functionality.