Fix operator in EVENT/UTIL namespaces

[rete]

BEGINRELEASENOTES

• Moved all stream operator overloads of EVENT class types into EVENT namespace (moved out from UTIL namespace)
  ENDRELEASENOTES

[petricm]

Did you recompile all of iLCSoft after this change to see if you break something?

[rete]

Yes, it doesn't change anything for the current iLCSoft version.

The motivation is for the new streamlog interface. The current logging object in streamlog is std::ostream, but in the new version I use a custom one, derived from std::ostream. In this case I can't print LCIO objects using streamlog.

See: https://stackoverflow.com/questions/3891402/operator-overloading-and-namespaces

The stream operators for a class should be defined in the same namespace as the class definition.