First attempt of cleaning traverse.c, cleaning up needed.
move rm_shred_thread_pool_* to util and use them in traverse.c
A bit of renaming action...
Fix behaviour for passing directly symlink-files
More or less finished cleanup of traverse.c (150 lines less)
Merge branch 'develop' of https://github.com/sahib/rmlint.git into shred_hardlinks

Conflicts:
	src/preprocess.c
	src/shredder.c