Doghole movement controller; some collision improvements

build/gamesource/config/entities/defaults.ent

proj/sxgame/vs2013/sxgame.vcxproj

proj/sxgame/vs2013/sxgame.vcxproj.filters

sdks/bullet3

source/core/ModelPhysbox.cpp

source/core/ModelPhysbox.h

source/dseplugin/ModelFile.h

source/dseplugin/ModelLoader.cpp

source/dseplugin/ModelWriter.cpp

source/exporter_base/Exporter.cpp

source/game/BaseAnimating.cpp

source/game/BaseCharacter.cpp

source/game/BaseCharacter.h

source/game/BaseMover.h

source/game/DogholeMovementController.cpp

source/game/DogholeMovementController.h

source/game/FuncDoghole.cpp

source/game/FuncDoghole.h

source/game/IMovementController.h

source/game/LadderMovementController.h