Move all Doodle source code into the src/ subpackage and move the
publicly shareable stuff into lib/, for example lib/ui and lib/render.
This cleans up the git root and helps make the Doodle UI library more
easily publishable as a separate open source project. Currently both
lib/ui and lib/render import one or two things from doodle/src that need
to be broken apart.
Noah Petherbridge
a316bafb12