const-correct smartpointers

[Murray Cumming Comneon com]

I applied a temporary, and maybe useless, fix to ObjectPtr_var<>, to avoid
the masses of warnings:

http://cvs.gnome.org/lxr/source/orbitcpp/orbitcpp/orb-cpp/smartpointers/obje
ctptr_var.h#36
http://cvs.gnome.org/lxr/source/orbitcpp/orbitcpp/orb-cpp/smartpointers/obje
ctptr_var.h#93

To have proper const-correctness I think we need to avoid specifying the
pointer type to the template. See the comments for more clues. The
equivalent in mico doesn't seem to need to do this.

Murray Cumming
murrayc usa net
www.murrayc.com