- Fixed mozilla test breakage caused by python's obscure module
  loading rules.
- Made sure test.py propagates test failures out as the exit code of
  the script.
- Remove runtime calls to get number constants. Remove Heap roots for
  some special numbers.
- Fix typo in accessors.h.
- Changes CopyMap to not copy descriptors.  Adds
  CopyMapRemoveTransitions that copies non-transition descriptors.
  Changes interface of DescriptorArray::Copy operations to simplify
  them.


git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@21 ce2b1a6d-e550-0410-aec6-3dcde31c8c00