Episode xacml flavour does not render correctly at Opencast's end

[gregorydlogan]

Currently we're ingesting security/xacml+episode, which renders as security/xacml episode at Opencast's end. Escaping it with %2b does not work.

[gregorydlogan]

This is worked around with cfc412e

This appears to be related to the order in which ingests are done. If you
ingest files such that a call to _do_post occurs without files containing
something after you ingest a file containing a '+' character in its flavour
you will see it magically disappear the + from the next post. The major issue
debugging this is that this only disappears after the post is sent. It is
not visible from the Python side, but it shows up in the debugger in Java.

I suspect this is the requests_toolbelt setting an incorrect content type,
since '+' renders as ' ' depending on the content type. Further debugging required.

[gregorydlogan]

Filed upstream as opencast/opencast#2777