configure.ac (AC_CONFIG_FILES): The makefile handles pygst.py now.

configure.ac (AC_CONFIG_FILES): The makefile handles pygst.py now.

Original commit message from CVS:
2005-07-12  Andy Wingo  <wingo@pobox.com>

* configure.ac (AC_CONFIG_FILES): The makefile handles pygst.py
now.

* Makefile.am (install-data-local): Actually install pygst.pth to
the pythondir, not pyexecdir. Also install a properly sedded
pygst.py.
(pygst.py): Sed the builddir into pygst.py, and set not writable
(to avoid any confusion about which file to edit).

* pygst.py.in (_pygst_dir): Set _pygst_dir from one variable,
@PYGSTDIR@, which is manually sedded in from the Makefile, so that
it works both installed and uninstalled.