test.py: Print command line when starting http servers in case of '--verbose'

test.py: Print command line when starting http servers in case of '--verbose'

R=ricow@google.com

Committed: https://code.google.com/p/dart/source/detail?r=25862

[kustermann, 2013-08-07 08:43:29]

Please note that we'll only print it at the beginning when the servers have been
started.

[ricow1, 2013-08-07 08:49:20]

lgtm

[kustermann, 2013-08-07 08:52:32]

Committed patchset #1 manually as r25862 (presubmit successful).

[Emily Fortuna, 2013-08-07 16:25:36]

thank you!