add examples of inDDL in comment lines
add TestRotation.rb
add TestMaterialsManager.rb
clean up code
move Material to its own file
add TestMaterial.rb
add examples of inDDL in comment lines
move Solid, BasicSolid, CompoundSolid, UnknownSolid from SolidsManager.rb to Solid.rb
add TestSolidsManager.rb
add TestSolid.rb