Started the validator package, and added the `Optionable` class (sjl-monad-functions are totally WIP/experimental and not being used anywhere) and added some notes/comments here and there on some todos.
Progress on Validator and ValidatorChain (so far InputRangeValidator is looking good).
Cleaned up InRangeValidator and added NumericValidator, and RegexValidator (empty).
Fleshed out RegexValidator.
Added ValidatorChain and scaffolding for InputFilter and Input classes as well as did some small amendments to RegexValidator and AbstractValidator.
Backing up further progress on Input and InputFilter.
Finished up preliminary implementations of InputFilter and Input.
Wrote preliminary tests for `InRangeValidator` and `RegexValidator` and put all validator classes in the `validator` namespace (now sjl.validator...).
Progress on InputFilter, Input, and ValidatorChain.
Further progress on Input, InputFilter and ValidatorChain.
Updated input filter test so they pass and found a bug that causes validation to be skipped for Inputs with required set to false (InputFilter->validateInput needs refactoring).
Updated `InputFilter->validateInput` to return true by default.
Removed the `input` and `validator` namespaces on `sjl` (inorder to keeps things simpler).
Merge pull request #2 from elycruz/validators

Validator and InputFilter features