This is my first pass at a significant API improvement. I iterated on it for a
while and this is what I settled on. I look forward to continuing to evolve
this API as I get more feedback and experience with it! Please let me know
what you think!
### Breaking Changes
***thinker:** stop cancelling actions when they go under Picker thresholds ([4c72b3d1](https://github.com/zkat/big-brain/commit/4c72b3d11eaa42af4b99ccf9ea729306e589ada8))
***stages:** Strongly typed stages for BigBrainPlugin ([65ca646e](https://github.com/zkat/big-brain/commit/65ca646e3b92b178025591878e2df6a08714880f))
***builders:** Blanket impls for ActionBuilder and ScorerBuilder when Clone ([8bed75b5](https://github.com/zkat/big-brain/commit/8bed75b54a43c72b53fbf9e2605b942cb2c53214))
***api:** rename attach and hide it from docs ([6c64df4f](https://github.com/zkat/big-brain/commit/6c64df4fc1211abe19919a3628476b930b6e9919))
***choice:** return &Choice instead of cloning ([a76dcbb6](https://github.com/zkat/big-brain/commit/a76dcbb67d4f6ae402f03d22e8d526408d8d875f))
### Features
***example:** update thirst example ([edecc4c9](https://github.com/zkat/big-brain/commit/edecc4c95f76bcd69c042372140486f744f4ccea))
### Bug Fixes
***hierarchy:** make sure all the hierarchy stuff is set up properly ([372c13e2](https://github.com/zkat/big-brain/commit/372c13e207523ec919c6490682f628f7d21cebea))
