Removed a few todo comments
fixed missing \n
added new element to RmFile which is a pointer to the file's hardlink
Added optimisation to skip checksum of hardlinked files
(Now only checksums and fingerprints the first of each set of hardlinks,
and sets a pointer in the other ones to point to the first one)
Modified RmFile initiator to set new hardlink pointer to NULL
Modified rm_file_list_remove_double_paths to set this hardlink pointer when hardlinks are found.
Extra detail for debugging messages
Style cleanup (astyle, google)
'/usr/share/man/man1Merge branch 'hardlinks_speedup' of https://github.com/SeeSpotRun/rmlint into develop
Fixed the -f option, symlinks are followed.

If -f is not specified, symlinks are completely ignored.
Special case: if symlinks are given as root arguments, i.e. passed
as dir to rmlint, they will be followed anyway for convinience.