Add TableSubsetter and subset_table
Merge branch 'death-march' of github.com:biom-format/biom-format into death-march
Add unit tests for TableSubsetter
Deprecate subset_biom.py
Add TableSubsetter tests to all_tests.py

Really starting to not like all_tests.py... :(
Merge pull request #178 from jrrideout/death-march

Convert subset_biom.py to pyqi