Allow create resource model in runtime; some shadow fixes

build/config_editor.cfg

source/core/ResourceManager.cpp

source/core/ResourceManager.h

source/game/PropStatic.cpp

source/light/light.cpp

source/light/shadow.cpp

source/render/shadow.cpp

source/render/shadow.h

source/terrax/terrax.cpp

source/xcommon/resource/IXResourceManager.h