Add file store method to rename
Use tmp directory for extracting unmanaged files

During inspection unmanaged files are extracted to the file store
"unmanaged_files.tmp".
The directory gets renamed as soon as the inspection is finished.

This allows debugging after canceling the inspection and also prevents
overwriting of working data.

If unmanaged_files were extracted before the file store is kept until
the new inspection is finished to keep the system description state
consistent.

Fixes #160
Mention tmp directory during unmanaged files inspection cancelation

Unmanaged files are now extracted to a temporary directory. If the user
cancels the process he gets a message where these partly extracted files
are available.
Merge pull request #207 from SUSE/extract_unmanaged_files_to_tmp

Extract unmanaged files to tmp