Fixed a memory leak in cPrefabPiecePool.

The pool pieces weren't freed upon pool destruction.
for compiliers other than msvc we need to tell lua that its building as a dll
FreeBSD requires __POSIX_VISIBLE macro to be defined
derp
Cmake system name not System name
Fixed a crash in message formatter.

The code would fail if a message is sent to a player not yet added to a world.
Merge remote-tracking branch 'origin/master' into VillageGen
Fixed a memory leak in cPOCPieceGenerator