add test cases for VM tunnelled migration with SSH, TCP and TLS Transports

This PR is based on PR1875, PR1882, and PR1884 and PR372.

[root@client virt-test]# ./run -t libvirt --tests type_specific.io-github-autotest-libvirt.virsh.tunnelled_migration.positive_testing.with_ssh --no-downloads --keep-image --keep-image-between-tests
SETUP: PASS (0.30 s)
DATA DIR: /var/lib/virt_test
DEBUG LOG: /home/ajia/Workspace/virt-test/logs/run-2014-11-14-16.14.14/debug.log
TESTS: 1
(1/1) type_specific.io-github-autotest-libvirt.virsh.tunnelled_migration.positive_testing.with_ssh: PASS (23.98 s)
TOTAL TIME: 24.04 s
TESTS PASSED: 1
TESTS FAILED: 0
SUCCESS RATE: 100.00 %
[root@client virt-test]# ./run -t libvirt --tests type_specific.io-github-autotest-libvirt.virsh.tunnelled_migration.positive_testing.with_tcp --no-downloads --keep-image --keep-image-between-tests
SETUP: PASS (0.30 s)
DATA DIR: /var/lib/virt_test
DEBUG LOG: /home/ajia/Workspace/virt-test/logs/run-2014-11-14-16.14.48/debug.log
TESTS: 1
(1/1) type_specific.io-github-autotest-libvirt.virsh.tunnelled_migration.positive_testing.with_tcp: PASS (29.70 s)
TOTAL TIME: 29.77 s
TESTS PASSED: 1
TESTS FAILED: 0
SUCCESS RATE: 100.00 %
[root@client virt-test]# ./run -t libvirt --tests type_specific.io-github-autotest-libvirt.virsh.tunnelled_migration.positive_testing.with_tls --no-downloads --keep-image --keep-image-between-tests
SETUP: PASS (0.30 s)
DATA DIR: /var/lib/virt_test
DEBUG LOG: /home/ajia/Workspace/virt-test/logs/run-2014-11-14-16.15.27/debug.log
TESTS: 1
(1/1) type_specific.io-github-autotest-libvirt.virsh.tunnelled_migration.positive_testing.with_tls: PASS (45.70 s)
TOTAL TIME: 45.75 s
TESTS PASSED: 1
TESTS FAILED: 0
SUCCESS RATE: 100.00 %


Signed-off-by: Alex Jia <ajia@redhat.com>