xotclInt.h

- based introspection for procs/instprocs on new argument definition structures
- allowing type checkers also for positional arguments
(for now only, when nonpos args are given as well; we have
to think about using these either for all procs/instprocs,
or only, when e.g. type checkers are used; we have to
make more benchmarking to get a better foundation)

- registered the following type checkers for procs/instprocs:
switch, integer, boolean, object, class

Example
o proc bar {-enable:switch o:object c:class} {
return "o=$o c=$c"
}

- generated interface for ::xotcl::configure; now 97 interfaces are
generated; shortcoming for bool/int converter stubs: optional
0-vaues are not recognized, so use tclobj for the time being

- extended regression test