fixes to allow-multiple-connections-per-ip and a unit test that run a swarm of 3 local peers

test/Jamfile

@@ -21,6 +21,7 @@ test-suite libtorrent :
 	[ run test_ip_filter.cpp ]
 	[ run test_hasher.cpp ]
 	[ run test_metadata_extension.cpp ]
+	[ run test_swarm.cpp ]
 	[ run test_allocate_resources.cpp ]
 	[ run test_web_seed.cpp ]
 	;