[GDnative] add pluginscript \o/

modules/gdnative/pluginscript/SCsub

@@ -0,0 +1,9 @@
+#!/usr/bin/env python
+
+Import('env')
+Import('env_modules')
+
+env_pluginscript = env_modules.Clone()
+
+env_pluginscript.Append(CPPPATH=['#modules/gdnative/include/'])
+env_pluginscript.add_source_files(env.modules_sources, '*.cpp')