Update annotate_group_sig and fix parse_KEGG

Updated annotate_group_significance.py to use parse_KEGG but NOT KEGG_Parser class. Fixed get_ko_names() from parse_KEGG.py so that name and definiton are reset for each KO since names were carrying over.  Gives better names if name and definition are avaliable.
Merge branch 'master' into laptop
Network updates and new merge_otus.py

merge_otus.py adds functionality to collapse a list of otu's from a biom table into a single entry in order to test changes in custom groups of otus.

Some changes to metab_network.py and new make_network.py scrpit.  make_network.py is designed to be a new more generalizable network generator.  With print network class that should be able to print any desired network.  TODO: add Network named tuple which should be easy to pass around and eventually send to print_network().
Merge branch 'laptop'