accept some strings as boolean
Update README.md

d'oh
Insignificant fix
added missing ModelException import when calling validate_instance with validate_all=True
Merge pull request #102 from bdickason/patch-1

Insignificant fix
Improving comments
Begining some rearrangements of the way Types are constructed. This commit makes it possible to override the name of a field in serialization. It favors a minimized field name of this override, but will use this override for all non minimized serilaizations.
Fixed incorrect handling of None during serialization in DateTimeField
Added a demo to show how you can change the name a field has during serialization
Merge branch 'master' of github.com:j2labs/schematics into sane_field_handling
Removing comments that are no longer necessary
More unnecessary comments removed
Removing only instance of NotAModelException
First draft of the new validation system is kind of working. I have not applied it to the whole branch yet, but I need to save here.
Merge pull request #103 from yalon/master

Added missing ModelException import
Added new path-related types.

Useful to validate configuration-related fields, where you want to check that a directory or a file exists or that a path can be written to or executed.
fixing a typo
This commit puts in place the last pieces of the new the validation system.

There are now three types of validation oriented responses, TypeResult,
FieldResult, and ModelResult.

A TypeResult respresents the result of a calculation at the Type level.  If
a value cannot be coerced into the type, for example.

A FieldResult represents something that happens at the level of an instance of
a type, aka a field.  If one is configured badly, etc.

A ModelResult carries information about the integrity of a model's design.

All of the validation functions at the field level and model level now return
one or more of those values.

Validation on a model is expanded into validation across all of the fields, or
across an expanded `ModelType` and the return values from the fields, which are
FieldResults, are processed into ModelType results to be returned from models.

This mostly completely my idea for a fully exposed validation tree of structures
which can be used to produce error reports as easily as html forms.

After all this work I am really pleased with the namedtuple approach.
merge conflict handled
Merge pull request #104 from yalon/master

Path-related types