hg serve: add clearer message when starting the server with --verbose
Explicitly tell the address is the one the process is bound to.
Fix the printing of IPv6 addresses.
# should print nothing
# should fail
abort: path 'b/x' is inside repo 'b'
abort: path 'b/x' is inside repo 'b'
# should fail
abort: path 'b/x' is inside repo 'b'
# should arguably print nothing
# should fail
abort: path 'b/a' is inside repo 'b'