- Use full paths for Rez and DeRez, which may not be on $PATH. Fixes bug
#509074.
- Also install the Tools directory on "make installmacsubtree".
- Added a note that you have to add Mac/Lib to sys.path after doing
a "make installmacsubtree".
- Include errors.rsrc in the Python.app resource file, so the error strings
are available in MacOS API exceptions.