Merge pull request #780 from BenjaminVanRyseghem/classifier

Adds more convenient testing methods on String
Moves `beginsWith:` and `endsWith:` to `SequenceableCollection`
- fixes SequenceableCollection >> endsWith:
- adds tests new SequenceableCollection methods
Small fixes for helios generators
strat to implement chain of responsibility
Merge remote-tracking branch 'upstream/master' into classifier
Passes done over the classifier

- Introduces a `chain of responsibility` pattern
- Renames `execute` into `classify`
- Renames `classify` into `doClassify`