Changelog for Falcon 0.3.0

Breaking Changes

Date headers are now returned as :pydatetime.datetime objects instead of strings.

This release includes a new router architecture for improved performance and flexibility.
A custom router can now be specified when instantiating the :pyAPI class.
URI templates can now include multiple parameterized fields within a single path segment.
Falcon now supports reading and writing cookies.
Falcon now supports Jython 2.7.
A method for getting a query param as a date was added to the :pyRequest class.
Date headers are now returned as :pydatetime.datetime objects.
A default value can now be specified when calling :pyRequest.get_param. This provides an alternative to using the pattern:
```
value = req.get_param(name) or default_value
```
Friendly constants for status codes were added (e.g., :pyfalcon.HTTP_NO_CONTENT vs. :pyfalcon.HTTP_204.)
Several minor performance optimizations were made to the code base.

The query string parser was modified to improve handling of percent-encoded data.
Several errors in the documentation were corrected.
The :pysix package was pinned to 1.4.0 or better. :pysix.PY2 is required by Falcon, but that wasn't added to :pysix until version 1.4.0.