Added log points for the end of the startup phase and the start of the init phase.
Added synchronization point handling
Added synchronization points 'start' and 'end' which are expected to be registered by an execution manager federate
Added exeuction manager federate
Moved CallbackBuffer into common package
Updated the package for CallbackBuffer
Moved FederateAmbassador to common package
Changed the package from federate to common
Corrected package declaration. Wrote 'callback' instead of 'common'
Imported new locations for CallbackBuffer and FederateAmbassador