Makefile: rename not to be used by make by default

Makefile → make_tarball

@@ -15,9 +15,9 @@
 #    along with this program; if not, write to the Free Software
 #    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
 #
-SRC_FILES := configparser.py connection.py dep_solver.py fetch.py\
-flow.py flow_altera.py global_mod.py hdlmake_kernel.py\
-__main__.py makefile_writer.py manifest_parser.py module.py msg.py path.py \
+SRC_FILES := configparser.py dep_solver.py env.py\
+flow_altera.py global_mod.py hdlmake_kernel.py __main__.py\
+makefile_writer.py manifest_parser.py module.py module_pool.py path.py \
 srcfile.py vlog_parser.py new_dep_solver.py
 SRC_DIR := src