expr: add Label term
compute: python Label
compute: pandas label
compute: sql label
expr: ReLabel term
expr: bigger test on relabel - join
relabel join test in python
compute: pandas relabel
compute: relabel sql
py3 fix
Merge pull request #290 from mrocklin/label

Label
expr: add basic Map operation
compute: python map
squashme
compute: pandas map
get apply from compatibility for py3 support
add apply to compatibility
expr: apply term
fix python map tests
compute: python apply