[master] for #1274, Use python_PYTHON for the python scripts

Use python_PYTHON for the python scripts. This results in
installing byte compiled version.

Removed files from EXTRA_DIST as they are now in dist by default.

Added CLEANFILES to clean up .pyc in build directory.

Note that I am keeping the installation directory the same.

src/bin/cfgmgr/plugins/Makefile.am

@@ -1,11 +1,14 @@
 SUBDIRS = tests
-EXTRA_DIST = README tsig_keys.py tsig_keys.spec
-EXTRA_DIST += logging.spec b10logging.py
+
+EXTRA_DIST = README logging.spec tsig_keys.spec
 
 config_plugindir = @prefix@/share/@PACKAGE@/config_plugins
-config_plugin_DATA = tsig_keys.py tsig_keys.spec
-config_plugin_DATA += b10logging.py logging.spec
+config_plugin_DATA = logging.spec tsig_keys.spec
+
+python_PYTHON = b10logging.py tsig_keys.py
+pythondir = $(config_plugindir)
 
+CLEANFILES = b10logging.pyc tsig_keys.pyc
 CLEANDIRS = __pycache__
 
 clean-local: