Current state of duchain/parser

[Kris Wong]

> Generalize it, so that it can be used for languages other than C++.
> Make the C++ one just a specialization of the general duchain.

I did quite a bit of work in this area this past Sunday.  Here's an
overview of the changes:

1. Moved the majority of duchain into lib/language/duchain
2. Added one additional interface, ICodeHighlighting, in
lib/language/interfaces
3. Moved the remaining C++ specific classes (builders, c++ type classes,
and type repository) from languages/cpp/duchain to
languages/cpp/duchainbuilder

None of this is committed yet, mainly because this is going to be quite
a task in svn.  Matt R had suggested using the svn move command to move
the files around, but it seems this does not support moving between
repositories.  Is there a way to go about this w/o having to
remove/re-add the files (thus losing history information)?  I was
planning to do this this evening (around 10:00 EST).  Unfortunately, no
matter how I go about this, it's not exactly going to be atomic.  I
would be cautious in doing an svn up for a short while after this time.

Kris Wong