Find first entries for each new group.

Begin split by determining which entries should begin new groups.
Choose which entry to group next.
Begin sorting remaining entries.
Always work with width first, height second.

Just conventional changes.
Remove example code.
Indent to four spaces.
Compiles.
Notes and tidy.
Rough draft of an initial test to pass.

Try and partition seven Michigan cities. See what we get.
Implement and test split(). Complete v0.0.1.
Functioning partition.
A reasonable partition with areas.
Remove dead test.