macstrerror - strerror which uses 'Estr' resource to convert numerical
MacOS errors to strings.
PyErr_Mac - Raise exception with MacOS error in string form.
PyMac_Idle - better idle-loop routine, which allows the user to
switch applications.
versions -- they now share config.c and config.h, and statting is
always done through macstat.[ch] (THINK's <stat.h> defines funny
constants). Also the configuration of stdwin is done differently: you
have to define USE_STDWIN to the compiler prefix.
