v0.0.0, 2014-02-19 -- Project Start

v0.1.0.3, 2014-03-03 -- Validation, coercion, forms, schemas
This version supports Python 3.x.
- `validate`: Validate data against a schema.
- `@validation`: Add input/output validation to a function.
- `CoercionManagerBase`: Parent class for coercion managers. Subclasses declare
  coercion methods for input and output.
- `coerce_input` and `coerce_output`: Coerce data with a schema, using the
  coercion methods declared on a subclass of `CoercionManagerBase.
- `@coercion`: Add input/output coercion to a function.
- `ValidationError`: Raised when validation fails.
- Schema types: Special types for defining schemas. Includes `AnyType`,
  `DictOf`, and `ListOf.
- Validators: Define validators as classes or functions. Add validators to a
  schema using tuples.
- `validators`: Pre-defined validators for common use cases. Includes
  `Required`, `OneOf`, `Range`, and `Regex`.
