Log Message:
Update to 1.2.1. Set LICENSE. Split off options into options.mk.

Version 1.2.1 (released 18 Apr 2009)

	* Remove signbit() from ProjectionIcosagnomonic.cpp

	* Add shadows from satellites on Saturn's rings, let brightness of
	rings go to zero as Saturn approaches equinox.

	* Add trail_output option to satellite files to print out
	satellite positions.

	* Calculate eclipse shadows a little past the terminator so they
	don't get cut off sharply.

	* Reload satellite files in case TLE files are updated between
	renderings.  Suggested by Lutz M

	* Added Lambert Equal Area projection

	* Check that -origin above or below is not specified for the Sun.

	* Added a definition for signbit() in ProjectionIcosagnomonic.cpp

	* Add patch from Doug Hawkins to support marker_* keywords in
	config file.

	* Added the -label_body option.  This is useful in conjunction
	with -separation to specify which body the label should apply to.

	* Added the -separation option.  This places the observer at a
	point in space where two bodies have the specified separation.

	* Allow -glare 0 to remove sun glare.

	* Fixed a bug where arcs were sometimes not drawn if they were
	vertical or horizontal lines.

	* A thickness value may now be specified for arcs.

	* Added max_radius and min_radius keywords to marker files.  This
	disables drawing of the marker if the planet radius is larger than
	or smaller than the specified value, respectively.

	* Fixed a bug where the arc color was not reset to the default
	color for subsequent arcs in the file.