Various work towards a basic game implementation

Get rid of some virtual functions that weren't needed.
Fix some functions to work during static init if need be.
Units now have unique incremental IDs

game/unit.cpp

@@ -3,6 +3,25 @@
 // Unit types
 #include "unitv.h"
 
+namespace
+{	
+	// Helper function for generating unique unit ids during static init
+	unit_id_t get_unique_unit_id()
+	{
+		static unit_id_t p = 0;
+		return p++;
+	}
+}
+
+CUnit::CUnit()
+: unit_id ( get_unique_unit_id() )
+, team_id ( team_id_invalid )
+, player_id ( player_id_invalid )
+, unit_vis ( unitVis_invalid )
+{
+
+};
+
 std::unique_ptr<CUnit> CUnit::getUnitFromVis( unitVis_c vis )
 {
 	switch( vis )