Upgraded include tag to use resolution keyword method.

__include.cpp

@@ -10,6 +10,7 @@ namespace jet {
       if(hasContainer)
 	throw coreutils::Exception("include tag should not have a container.");
       hasContainer = true;
+      resolveKeyword("file");
       coreutils::File file(variables["file"]);
       file.read();
       container = file.asZString();