Add docstrings to the code so far written.
Normalize URI from configuration keys.
Add basics of version processing

Adds the basics of version processing.  This includes an __call__()
method implementing the actual application; the _process() method
to process the full request; a Result class to simplify some
aspects of processing; the implementation of the _proc_uri() method
to process the URI; and an initial framing of the
_proc_ctype_header() and _proc_accept_header() methods.
Create a header utility routine

Create a routine that can help process a list separated by a given
character when the elements of that list may have that separator
within double-quoted sections.  This will be used both to parse the
multiple options of an Accept header, as well as to parse the
parameters of an individual content type.
Create a parser for content types and parameters

Create a parser using quoted_split() to process a single content
type.  Returns the content type and a dictionary of content type
parameters.
Add a parser and representation for Accept.