use Rsconscript instead of Rsconsfile - close #62

build_tests/build_dir/Rsconscript

@@ -0,0 +1,5 @@
+Rscons::Environment.new do |env|
+  env.append('CPPPATH' => Rscons.glob('src/**'))
+  env.build_dir(%r{^src/([^/]+)/}, 'build_\\1/')
+  env.Program('build_dir.exe', Rscons.glob('src/**/*.c'))
+end