…eleases

* Rename "Modules/random.c" to "Modules/bootstrap_hash.c"
  See python/cpython@6b4be19
      bpo-22257: Small changes for PEP 432. (#1728)
      PEP 432 specifies a number of large changes to interpreter startup code,
      including exposing a cleaner C-API. The major changes depend on a number
      of smaller changes. This patch includes all those smaller changes.

* Remove bundled copy of libffi (Closes #27979)
  See python/cpython@f40d4dd
      An installed copy of libffi is now required for building _ctypes on
      any platform but OSX and Windows.

When configuring the project with -DSRC_DIR:PATH=/path/to/src/Python, this
commit makes sure that the python version associated with the source
directory is associated with the PYTHON_VERSION cache variable.

… module

drop random.c
add
call.c
bootstraph_has.c
ast_opt.c
ast_unparse.c
pathconfig.c
context.c
hamt.c

…leted in commit d185c6e.

…e as an extension.