Add a script to edit path of in-place imported images

[Tom-TBT]

New script to work on the path of in-place imported images.

The script aims to validate the changes as much as possible before editing the path stored in the database and before editing the symlinks.

• Same checks as the Fileserver_import script (user is allowed to access data on the target fileserver, no backward reference)
• Ensure that path to replace is found only once (no ambiguity allowed)
• All new path are targeting files from the same Group from the data access validation (cf Fileserver_import config)
• New symlink points to a valid file
• Target file have the same size as the old
• opt: target file checksum matches the old checksum
• Updated images are in-place imported
• User has permission to edit the Fileset object in OMERO

Once that the checks pass, the symlinks are created in three steps:

• Generation of a temp symlink
• Deletion of old symlink
• Renaming of the temp symlink
  If this is successful, then the clientPath of the Fileset_Entry is updated.