steven-omaha
0381fc7525
The first attempt 02c44c92d0 caused
`Section.partial_cmp` and `Section.cmp` to call each other recursively.
That lead to a stack overflow when compiled without optimizations, and
an infinite loop when optimizations were enabled.
This commit now properly implements at first `Ord` for both `Section`
and `Group`, and from this derives `PartialEq` for each.