Fix conversion of PICRUSt files

Fixes #148
Merge branch 'master' into issue148
remove space from test dataset
add metadata support for CommandOut
specifying output right...
table converter now supports CommandOut
show install info and table subsetter using CommandOut
more commands up to speed

cleaned up table summarizer some and compute_counts_per_sample_stats
validate table now up to speed
removed comments
Add scipy import check to biom.__init__.py
Changes to address @wasade comments.
Fixed small conflict with PR.
Merge pull request #234 from wasade/pyqi_outcmds

Pyqi outcmds
updated changelog to be compatible with pyqi
added release date
Small fixes to PR and test case.
removed release date...
Merge pull request #250 from wasade/changelog_fix

Changelog fix
pyqi now required, dateutil now extras