data_* -> data
Merging upstream master
ENH: normalize by metadata
Merge pull request #336 from josenavas/data

Data
Remove norm_by_metadata function and assoc tests
Merge pull request #337 from adamrp/norm_by_metadata

ENH: normalize by metadata
Merge branch 'master' into norm

Conflicts:
	biom/table.py
	tests/test_table.py