degesch: add the first Lua plugin to distribution

This required separate plugin directories for both pluginized executables.

config.h.in

@@ -2,7 +2,7 @@
 #define CONFIG_H
 
 #define PROGRAM_VERSION "${project_VERSION}"
-#define PLUGIN_DIR "${CMAKE_INSTALL_PREFIX}/${plugin_dir}"
+#define ZYKLONB_PLUGIN_DIR "${CMAKE_INSTALL_PREFIX}/${zyklonb_plugin_dir}"
 
 #cmakedefine HAVE_READLINE
 #cmakedefine HAVE_EDITLINE