md5checker.py: reimplement directory checking to operate on a file-by-file basis.
md5checker.py: reimplement directory checking to operate on a file-by-file basis.

Directory checking previously worked by generating all checksums for one directory in a temp file and then checking the second directory against this file. The new version does direct comparisions of each pair of files, avoiding the intermediate file and generating screen output sooner.

fw1121/genomics,fw1121/genomics,fw1121/genomics,fw1121/genomics,fw1121/genomics