refactored sizeof_ptype, sizeof_stype to make them available from static context
first parts of copy_ptype with unit tests
-refactored compare_stype a bit
-added copy_stype method with first bits
-added first unit test for copy_stype
initial (working) attempt for a general purpose clone method of CSGObject. Comes with first basic unit tests. More to come
Merge pull request #1167 from karlnapf/develop

first attempt for general clone method