Improve error handling during import (See #10090) (rebased onto develop)



This is the same as gh-580 but rebased onto develop.

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Improve error handling when an error occurs during import. Problem noticed while testing FS import.
See http://trac.openmicroscopy.org.uk/ome/ticket/10090

To test:

Choose an image that does not import see https://docs.google.com/spreadsheet/ccc?key=0AuqP9_Rq_HgldDNjT0ZIcHRSOUg1OFpjVUthdzM4cmc#gid=8