exchange: use rich class for sorting clone bundle entries
Python 3 removed the "cmp" argument from sorted(). Custom sorting in
Python 3 must be implemented with the dunder comparison methods on
types and/or with a "key" function.
This patch converts our custom "cmp" function to a custom type.
The implementation is very similar to functools.cmp_to_key(). However,
cmp_to_key() doesn't exist in Python 2, so we can't use it.
This was the only use of the "cmp" argument to sorted() in the code
base.
Added signature for changeset
e69874dc1f4e
Added tag 4.0.2 for changeset
e69874dc1f4e