Adjust factory method to follow Flask extension guidelines
Adjust test for `init_app`
Refactored part of fields.List.output() into List.format() so that the field can be properly applied to single values
Added marshal_with_field decorator and basic tests
Added 'marshal_with_field' to __all__
Added docs references for marshal_with_field
Fix fields.Float to output actual floats per JSON spec
Merge branch 'factory-fix' of https://github.com/mattupstate/flask-restful into mattupstate-factory-fix

Conflicts:
	flask_restful/__init__.py
	tests/test_api.py
Merge pull request #222 from twilio/mattupstate-factory-fix

Mattupstate factory fix
whitespace fixes. one space in classes, else two
Merge pull request #223 from twilio/whitespace

Whitespace fixes
Merge pull request #214 from lyschoening/marshal-with-field

Added marshal_with_field decorator, see issue #212
Merge pull request #219 from twilio/fix-float-field

Fix fields.Float to output actual floats per JSON spec
Adds custom error handling
Users can define a dictionary of what messages and status codes to return when certain exceptions/errors are encountered during a request.
Fixes #221
Adds information about custom error messages to the docs
Adds unit test for custom user messages
Fix import for Python 3 support
Merge pull request #231 from pswaminathan/py3

Fix UserDict import for Python 3 support
Merge pull request #225 from computmaxer/custom_error_handling

Ability to define custom error messages