[GCC-XML] Managing include paths and the support dir

[Tony]

Hi Brad,

First off, thanks for gccxml. I love this tool! gccxml makes all
compilers seem silly that they don't provide this kind of feature.

I am using MSVC9, and that works well. I want to use STLPort instead
of the default Dinkumware STL and I am willing to manually create a
support directory to ensure that all works nicely.

My current challenge is that I am not sure I see how to do one of the following:
* include my own path before GCCXML_FLAGS (i.e. GCCXML_PRE_FLAGS)
* specify the support dir I want to go in manually.

For example I'd love to say:

if (USE_STLP)
	gccxml --supportdir "vc9_stlp"
else
	gccxml --supportdir "vc9"

I know you can specify a compiler, but that checks the registry to
find out where to look. Is there a way to get more control than that?

Do you have any advise? If not I'd like to log a feature request! (I
am also anticipating some tinkering with boost v. tr1 support in the
near future ahead of gccxml's official support of it)

For the short-term I'll probably copy my support/vc9 dir to
support/vc9_orig and overwrite vc9 with stlp support stuff, but I'd
like to conserve gccxml's form more if possible.

Thanks!

// tony