rename layout to type

this one goes to caleb for pointing it out.
Much better word

test/soml/statements/test_fields.rb

@@ -41,7 +41,7 @@ HERE
       @string_input = <<HERE
 class Space
   int main()
-    Layout l = self.layout
+    Type l = self.type
     return 1
   end
 end

test/soml/statements/test_return.rb

@@ -49,7 +49,7 @@ HERE
 class Space
 
   int main()
-    Layout l = space.get_layout()
+    Type l = space.get_type()
     return self.runner
   end
 end