Merge pull request #7 from oroulet/master

small fixes and work on subscription interface
Merge pull request #8 from oroulet/master

high level subcsription interface, fix subscription bug
start implementation of event support, small cleanup and work on ubscription api
theoretical implementation of DeleteMonitoredItems
add deletemonitoreditem in opc_tcp processor
theoretical fix to MonitoringFilter serialization, move monitoringitens implementation to correct cpp file