I think the fix for opensslconf.h path (/usr/include/x86_64-linux-gnu/openssl/) should be applied to all debian distribs (at least >= Jessy).
In my case, i'm developping under Ubuntu 15.04 and packaging my app with Docker Python 2.7, so on Debian Jessy. In both distribs the opensslconf.h file is at the same location.
BTW, do you know what's the situation with M2Crypto ? Is it maintained or what ?