Fix Eventer race

This test reports the race condition when run
using "go test -race".

The new event machine will be used for loose coupling and handle the
communications between the services:

1) Block pool finds blocks which "links" with our current canonical
chain
2) Posts the blocks on to the event machine
3) State manager receives blocks & processes them
4) Broadcasts new post block event

Add blank line after +build comment

Conflicts:
	peer.go