define more types

define more types

* figl/parse.scm: Don't reduce pointer types to "*" early on.  Instead,
  try to preserve the information that we have.

* doc/low-level-gl.texi:
* doc/low-level-glu.texi:
* doc/low-level-glx.texi:
* figl/glx/low-level.scm:
* figl/glu/low-level.scm:
* figl/gl/low-level.scm:  Regenerate.

* figl/gl/types.scm:
* figl/glu/types.scm:
* figl/glx/types.scm: Define more types.