I have just tried to install Bullet with help of Cmake. And i found an error in bullet-2.70/src/BulletCollision/CMakeLists.txt file.
Original
CollisionShapes/btMultiMaterialTriangleMeshShape.cpp
CollisionShapes/btMultiMaterialTriangleMeshShape.h
it should be
CollisionShapes/btMultimaterialTriangleMeshShape.cpp
CollisionShapes/btMultimaterialTriangleMeshShape.h