In order for RBTools to make intelligent decisions about what binary

files to upload to the server, we're exposing a list of supported MIME

types to the server capablities blob. This is populated from the

registered ReviewUI classes, and then we add manually the MIME types

supported by Power Pack (in order to optimistically have the client

upload files, even if the feature isn't yet licensed).

Verified that the correct data was in the server info API response.
Ran unit tests.