Check if user has altered 404 error
Fix indenting in custom 404 msg.

Add a test
assert that message is added by default
Add prettyprinting for JSON.

This commit adds prettyprinting to JSON output in two ways:
    1. It creates a 'settings' dict in the JSON representation module
       that contains kwargs to be passed to json.dumps.
    2. When the app is in debug mode (app.debug is True), then the
       representation will set reasonable defaults for prettyprinting
       JSON - specifically, indenting by 4 spaces and sorting by keys.
       Note that both of these values will not be set if there is an
       existing setting for them.

Tests are also added.
Merge branch 'master' into andrew-prettyprint-json
fix typo
Add pycrypto to optional module

It's not used by core code at the moment
bump to 0.2.2
install pycrypto before running tests
Add travis.yml
add testing docs
add docs extra
add comment
add more targets to Makefile
adding allow_null param to nested fields to supress now show children when none exist
Fix bug when a non-dict was marshalled with a fields.List.  Fix just uses the same attribute access style of other field classes.
Document the Nested data type
add another test to verify the behavior
Merge pull request #86 from davidcrawford/fix-list-field

Fix bug when a non-dict was marshalled with a fields.List.
Update fields.rst