Support multiuser segmentation

[che85]

From discussions with @DoraSzasz, they were having problems when several users work on the same series because one user cannot see the segmentation of another.

There are several ways for supporting that:

• display all segmentations available (regardless of the creator)
• display only all most recent segmentations (if several segmentations of the same object have been found)
• users might want to override a segmentation of another user which should a) give a warning and b) log this somehow and keep the old label in place and save the new one

@fedorov Any thoughts on this?

[DoraSzasz]

We solved this by not taking into account the username while we load the segmentation file:
globPath = os.path.join(self.resourcesDir, str(seriesNumber), "Segmentations", '*')

instead of:
globPath = os.path.join(self.resourcesDir,str(seriesNumber),"Segmentations",
self.getSetting('UserName')+'*')

in the "checkAndLoadLabel" method.

The segmentation files are thus visible by any user.