A couple of namespace+template bugs.

[Martin von Loewis]

> I haven't seen much discussion of these changes yet, but i thought the
> least i could do is send in a couple bug reports. :-)

Scott,

thanks for your reports. As a matter of fact, I have not looked into
templates inside namespaces, yet. It seems the template code is not
aware that a nested-name-specifier might be a namespace-name instead
of a class-name, so it does not know that it should do namespace
lookup.

Currently, I plan to proceed as follows:
- align lookup of type names inside namespaces, to support the
  proper shadowing semantics. See ns13.C for a remaining problem.
  (this is mostly done in my local copy)
- support using-directives.
- redo function overloading
Since I don't have a grasp on how g++ represents templates, yet, I'm
not sure how it would fit into this schedule. Since C++ is quite
restrictive as to how template names can be overloaded with something
else, it should be an independent matter.

Thanks to Jason for so quickly integrating this code. I'm very
interested to hear whether I broke something, so if anything that used
to work doesn't anymore, please let me know (there are no regressions,
so I hope it won't).

Regards,
Martin