enhanced-path issues

[Chris Nokleberg <chris@sixlegs.com>]

The spec for the draw:enhanced-path attribute says
  "superfluous white space and separators such as commas can be
   eliminated"

However there is no formal grammar for enhanced-path, and none of the
examples actually use commas, so it is unclear exactly what is means by
"separators such as commas".

The "N" command of enhanced-path is described thusly:

  "Ends the current set of sub-paths. The subpaths will be filled by
   using eofill. Other following sub-pathes [sic] will be filled
   independently.

I think "eofill" is a typo, but I'm not sure for what.

It should also probably be mentioned that by default sets of subpaths
are filled and stroked, unless the F or S commands indicate otherwise.

Also, the description of the ellipticalQuadrant commands indicate the
initial tangent, but do not specify the behavior of additional points in
the same command. Experimentally, the tangential axis alternates for
each point. For example the path "M 5 0 X 10 5 5 10 0 5 5 0 Z N" will
draw a circle--the initial tangent is to the x-axis, but the following
three points are tangent to the y, x, and y axes, respectively.

Thanks,
Chris