Added beginnings of new HeaderCollection class.
Added it to the package.
Added a few basic tests.
docstring
Expanded the constructor.
Filled in the get method.
Switched from try_* utility functions to using HeaderCollection. Removed the try_* utility functions.
Re-worked some tests.
Added a couple tests for HeaderCollection.
Revised the functional requirements, adding an explanation of Deproxy's relation to the formal specifications of HTTP.
Renamed requestline to request_line.
Re-wrote header parsing.
Cleaned up logging; removed trailing CR's and LF's from response line.
Updated TODO.
Merge branch 'fix-headers' into develop