deploy-ng: Change default model-cache-dir on deployed applications

We replace panda3d in the model-cache-dir ConfigVariable with the name
from setup.py.

direct/src/showutil/dist.py

@@ -315,8 +315,9 @@ class build_apps(distutils.core.Command):
                 ln = ln.strip()
                 useline = True
                 if ln.startswith('#') or not ln:
-                    useline = False
-                else:
+                    continue
+                if 'model-cache-dir' in ln:
+                    ln = ln.replace('/panda3d', '/{}'.format(self.distribution.get_name()))
                 for plugin in check_plugins:
                     if plugin in ln and plugin not in self.plugins:
                         useline = False