Remove redundant copyright from demos
Remove lib, move color to its own package

This includes some minor improvements to the Color class,
ported from the periodically updated gist.
Remove copyright from padlib, bump version

Next commit will feature a large rewrite of the Grid and Cell classes
to simplify things.  These are significant changes - coercion is gone,
as well as the idea of callback defaults:
-Previously, cells looked up default values from their grids if they
 didn't have that value.
-Now, cells look up defaults from their grids at creation time.
Rework Grid and Cell classes to simplify attribute resolution

particularly w.r.t. default values and when cells report updates back
to their grid.