C++ include path

[Matthew Dillon]

:Attached patch adds /usr/include/c++ as include directory for both compiler
:versions. It should be used for all in-tree C++ headers which are itself
:version independent [currently only lex].
:
:Joerg

    The patch looks good.

    We definitely want to do the double-pathing (BLAH and BLAH/compilerrev).
    Do you think we are going to hit any major problems by making BLAH 
    /usr/include/c++ instead of the FreeBSD /usr/include/g++ ?  

    I'm a bit undecided... I don't mind us using /usr/include/g++ and
    /usr/include/g++/<compiler_rev> instead of c++ and c++/<compiler_rev>,
    but the name 'c++' seems to be more compiler agnostic then g++, especially
    since we are breaking the compiler-specific files into their own
    <compiler_rev> sub directory.  I've been holding off cleaning up the
    old /usr/include/g++ in upgrade_etc until we come to a decision on how
    we actually want it to look.

    What do you think?

						-Matt