[Description] Defines the events raised by the build engine. Loggers receive an object implementing this interface in their Initialize method and use it to subscribe to the events they are interested in receiving. [Interface] 
IEventSource
I B u i l d E n g i n e
I E v e n t S o u r c e
I L o g g e r
I T a s k
I T a s k H o s t
I T a s k I t e m