Modified a single line in parse_classic_otu_table to allow it to correctly parse classic tab delimited OTU tables that do not have a leading comment line (fixes issue #678). Added a specific test for this case in test_parse_classic_otu_table. Ran all_tests.py to make sure it didn't break anything down stream and it appears not to have. The specific case I am resolving with this commit is where you sumbit a classic OTU table instead of a summarized OTU table to make_3d_plots.py as the biplot otu table (the -t option).
Fix for issue #677
Fix for issue #677
Merge pull request #681 from wdwvt1/parse_otu_table_fix

Modified a single line in parse_classic_otu_table to allow it to correct...
Addressing comments for merge
Addressing last comments for merge
Fixing typo
Merge pull request #683 from antgonza/fix_issue_#677

Fix issue #677
Resolves issue #686.

Updated 3 lines in compare_alpha_diversity.py to check if p_val or obs_t return as None because of low variance data passed to mc_t_two_sample. Updated the script documentation to identify this third source of error (why you would get None, None for pval, tval).
Merge pull request #689 from wdwvt1/issue686

Resolves issue #686.