Move label to measure module (with deprecation). Warn that background parameter will default to 0 in v0.12.
Move implementation of label to measure submodule
Fix imports and suppress deprecation warnings
Update bento build
Fix broken and circular imports
Mention which parameters to label are optional. Simplify label deprecation.
Avoid circular imports
Correctly apply catch_warnings()
Merge pull request #1007 from stefanv/label_refactor

Move `morphology.label` to `measure.label` and prepare for 0-label transition