Close the connector when the group is closed.
Register event
Change logging level to error on exception being thrown
Replace close by _del()_ and add null check
Merge pull request #701 from sbesson/rebased/develop/homebrewjob_fix

Fix OMERO-homebrew* jobs when Homebrew installation failed (rebased onto develop)
Close the reader when the import is done (see #10249)
Do not interrupt thread (see #10116)

As a general rule, Ice for Java does not work well in the
presence of thread interrupts.
see
http://www.zeroc.com/forums/help-center/
5057-ice-java-exception-ice-thread-pool-client.html
Pass the loader's id so it is removed from the map.
Pass loader id. Fix all calls.
Handle the case of image w/o pixels (see #10290)
Check the returned exception depending on pixels Id (see #10291)
Modify the error handling when checking if big image (see #10306)
Refactor code so no copy of settings is kept.
Set the current group correctly (see #10334)
Add doc.
Do no allow to add files to queue when loading data.
Fix import of plate and link to screen (see #10322)

The problem only occurs when a folder is selected and the
folder contains a plate and a non plate file.
Fix loading of data (see #10333)
Do keep reference to current group.
Add Javadoc for new unit tests.