Finally: support for enums that also makes sense in Python.
Fill in geometry.h, type.h, draw.h.  Make Quantum and MagickRealType sorta work.
Only ever pass bytes to the C API!
Add some cruft to .gitignore.
Add ImageMagick feature detection; merge in the "format" module.
Whoops, typo.
Fix format parsing on py3k.
Remove `emulate` arg to fit_area; apparently an IM bug, now fixed.
Fix most py3 incompatibilities.
Much improved crack at filters.  Also, other stuff.

- Filters now have a consistent API, whether wrappers for built-in
  ImageMagick functions or created out of Python functions.

- Simple Python filters can be compiled to a dumb C bytecode, which is a
  bit faster than Python.

- Color classes have been redesigned, made immutable, and made vaguely
  aware of colorspace.  Sort of.

- Added very basic support for creating an image from a gradient.
  Stubbed out the draw module, where this lives.