In falkor test runner FALKOR_SOCKETS env variable used for globalAgent.maxSockets

Hello anyone, 

Please review the following commits I made in branch 'dpup-runner'.

3a790dbb94b0f20dbdfaf4106d543014c176bbed (2013-04-01 10:23:14 -0700)
In falkor test runner FALKOR_SOCKETS env variable used for globalAgent.maxSockets

R=anyone