- Applications now have their (minimal) main prrogram in
  macapplication.c and the rest of the init code in macglue.c.
- A new define, USE_MAC_APPLET_SUPPORT, independent of
  USE_MAC_SHARED_LIB
- chdir to script directory now done in PyMac_InitApplication.

whether there is shared library support. Libraries, applets and
applications are distinguished by the sources they include.