Don't do a DNS lookup on a bridge line address

Fixes bug 10801; bugfix on 07bf274d in 0.2.0.1-alpha.
Add a test for default/port conflicts in tor_addr_port_parse
Make tor_addr_port_parse handle portless IPv6 addresses correctly.

(Not a bugfix on any Tor release; before 10801_024, it didn't handle
portless addresses at all.)
Merge remote-tracking branch 'public/bug10801_024'

Conflicts:
	src/common/address.c
	src/or/config.c