[WIP] Prepare code for production

[glouppe]

This is a PR to make sure everything is ready for production.

• [x] Add blocking strategy parameters, using NYSIIS as default
• [x] Switch to random forests instead of boosting
• [x] Add a "fast" version on a reduced set of features
• [x] Update documentation
• [ ] Run all to make sure it still works

[glouppe]

CC: @jmartinm @jacenkow

[jmartinm]

:+1: