Revert "Revert "CConnection.cpp: remove some unnecessary includes""

This reverts commit 14a27e3a45d47fad7e4d96d783a4ec8da9ec07ce.

Conflicts:
	Broker/src/CConnection.cpp
Rename DgiMessage and CsrMessage

DgiMessage will now be ModuleMessage. CsrMessage will now be
ProtocolMessage. (And ProtocolMessage can be used for all three
protocols. ;)