tmf: fix bug when importing and no project is selected

tmf: fix bug when importing and no project is selected

fix importing custom text and xml traces
fix importing single files in copy mode when one file is imported
several times, sometimes renamed after importing non-renamed versions of
the same trace

Change-Id: I70a13fdfd800bc46475040e6d73a86e19a6bbdc2
Signed-off-by: Matthew Khouzam <matthew.khouzam@ericsson.com>
Reviewed-on: https://git.eclipse.org/r/13289
Reviewed-by: Bernd Hufmann <bernd.hufmann@ericsson.com>
IP-Clean: Bernd Hufmann <bernd.hufmann@ericsson.com>
Tested-by: Bernd Hufmann <bernd.hufmann@ericsson.com>
Reviewed-by: Alexandre Montplaisir <alexmonthy@voxpopuli.im>
IP-Clean: Alexandre Montplaisir <alexmonthy@voxpopuli.im>
Tested-by: Hudson CI