RFE: Fix IMAP-send TCP connect

Request:  Somebody please fix imap-send.c to use git_tcp_connect() so 
that it supports IPv6 and getaddrinfo().

Bonus points for also fixing:

On Linux, daemon should use the default Linux behavior, binding to both 
IPv4 and IPv6 sockets at the same time.  git is actually doing _more 
work_ to avoid this.

	Jeff