python2.4: fix imports of sub-packages of the email package
These all have an obvious comment so if/when we finally ditch Python
2.4 we can eradicate them easily.
httpconnection: properly inject ssl_wrap_socket into httpclient (
issue4038)
This causes httpclient to use the same SSL settings as the rest of
Mercurial, and adds an easy extension point for later modifications to
our ssl handling.