The problem was that Share could be deleted *before*
the OcsShareJob itself finished. Since Share was the
parent of the network job, its object would be deleted
too early.
In general, it's unnecessary to assign parents to the OcsJobs
because they delete themselves when finished.
There is now a generic OCSJob which must be inherited by other jobs. This is in
prepartion for the other OCS job that will come (for the Sharee API endpoint
for example).
More logic is moved from the sharedialog to the OcsShareJob. So in the GUI code
we now only say what we want (a new share, set the password etc). And the code
in libsync will make that happen. Error handling is for now still done in the
GUI part.
For now the ocsjob and ocssharejob live in gui but probabaly we should
create a libshare or libocs at some point.
