Chore(Validator): Update comments, style nits.

Pass jsHint checks.
Fix(Validator): Make nulls no longer pass required check.

d’oh!
Improve(Validator): Add exact length case to strLen check.
Add(Validator): Add test case for numeric strings.
Add(Validator): Add arbitrary javascript validation method.
Add(Validator): Add regex validator.
Add(Validator): Add basic date string validator.
Improve(Validator): Objects without pretty name set will return validation name.
Improve(Validator): Code cleanup.