small fixes and code formating according to PEP8
map2slim, tests for map2slim, fixes

implemented the mapslim method of the map2slim.pl script from the
geneontology go-perl package ( http://search.cpan.org/~cmungall/go-
perl/scripts/map2slim )
map_to_slim command-line script
documentation and test into run.sh
fixed README formatting
Merge pull request #17 from r4d2/master

Added map2slim functionality using the goatools framework.