Minor changes and additions to triple slash comments.
Better example code to exemplify how to add custom argument validations.
Implemented IArgumentValidator.IsNull()
Implemented IArgumentValidator.IsNull(Func<string> exceptionMessageFactory).
Implemented IArgumentValidator.IsNull<TException>(Func<TException> exceptionFactory).
Implemented IArgumentValidator.IsEqualTo(...) (all overloads).
Implemented IArgumentValidator.IsNotEqualTo(...) (all overloads).
Implemented IArgumentValidator<Guid>.IsNotEmpty(...) (all overloads).
Implemented IArgumentValidator<string>.Matches(...) (all overloads).
Refactored unit tests for maintainability.
Implemented IArgumentValidator<T>.IsEqualToAnyOf(...) and IArgumentValidator<T>.IsNotEqualToAnyOf(...) (all overloads).
Removed 'EqualTo' from the names of all argument equality validation methods.
Change to example code in README.md.
Incremented version number in preparation for release.
Playground stuff.
Reintroduced 'EqualTo' in the names of all argument equality validation methods.
Playground stuff.