* calculate_path() rewritten in Modules/getpath.c and PC/getpathp.c
* Move global variables into a new PyPathConfig structure.
* calculate_path():
* Split the huge calculate_path() function into subfunctions.
* Add PyCalculatePath structure to pass data between subfunctions.
* Document PyCalculatePath fields.
* Move cleanup code into a new calculate_free() subfunction
* calculate_init() now handles Py_DecodeLocale() failures properly
* calculate_path() is now atomic: only replace PyPathConfig
(path_config) at once on success.
* _Py_GetPythonHomeWithConfig() now returns an error on failure
* Add _Py_INIT_NO_MEMORY() helper: report a memory allocation failure
* Coding style fixes (PEP 7)
Victor Stinner
0327bde9da