* lang/python/gpgme-h-clean.py: Delete file.
* lang/python/MANIFEST.in: Adapt accordingly.
* lang/python/Makefile.am (EXTRA_DIST): Likewise.
(COPY_FILES_GPG): Bring variable back.
(copystamp): Copy files.
(clean-local): Delete copied files.
(install-exec-local): Do not create and install list of installed
files.
(uninstall-local): Instead, create some explicit rules to uninstall
the extension.
* lang/python/setup.py.in: Parse arguments.  Locate files either in
the source directory, or in the build base directory.  Inline the code
from 'gpgme-h-clean.py'.  Copy 'helpers.c', add source directory as
include directory.