0.5.0

• Split off the Jolt Physics enums into a "joltjni.enumerate" package.
• Use GCC v9 when compiling for the Linux_ARM32hf platform.
• Added the RefShape class to the library.
• Added a no-argument constructor for MutableCompoundShape.
• Added 2 public methods to the library:
  • CompoundShape.getNumSubShapes()
  • Shape.toRef()