Fixes to communicator package as suggested by @illarionov

* Changing context scope.
* Moving closing cursor and submitter command into finally{}
* Deciding that all IOException` can be temporary (reduces data discarding).
* Cleanup if gzip fails: if gzipping fails, the AbstractCommunicator has to clean up first.
Merge branch 'network' of https://github.com/tamcap/MozStumbler into develop

Conflicts:
	src/org/mozilla/mozstumbler/sync/SyncAdapter.java