Misc py3 c modules

[github at samba.org]

New comment by catalyst-joe-guo on Samba Github repository

https://github.com/samba-team/samba/pull/152#issuecomment-377024686
Comment:
After fixing the bytes formatting and libname issue, this patch passed autobuild last night. I will create a new PR soon.

PS: Inline comments on github will not be sent to Samba email list, I will use the global comment box from now on.