Changed TIME_UTC to boost::TIME_UTC

On Ubuntu 12.10 with libboost1.49 I was getting the following errors:
shawn/src/apps/vis/events/vis_refresh_liveview.cpp:28:40: error:
‘TIME_UTC’ was not declared in this scope
shawn/src/apps/vis/events/vis_refresh_liveview.cpp:58:40: error:
‘TIME_UTC’ was not declared in this scope

The solution was straight forward: substitute TIME_UTC for
boost::TIME_UTC on vis_refresh_liveview.cpp The patched file goes in
attachment.