Test now pass in test_biom_validator.py

Fixes #174
Merge branch 'death-march' of github.com:biom-format/biom-format into death-march
Add TableValidator and validate_table
optparse command gives correct return value
Add unit tests for TableValidator.

Output is now more user-friendly.
Merge pull request #177 from jrrideout/death-march

Convert biom_validator.py to pyqi