Fixed missing type conversion of variable entities when encodings are
specified. E.g. using <foo a="&var.x:url;"/> where TagFoo has declared
"a" as RXML.t_int still gave a string in args["a"].
This problem is not new in 5.0, but it might possibly have compatibility
aspects so it is not fixed in older versions. Also, the problem rarely
manifests itself in older versions since the type system is less exposed