[v3] doc updates for setup

[Benjamin Kosnik]

This updates the setup section of the libstdc++ docs. 

tested x86_64/linux
gcc, 
gcc-4_3-branch after a few days

-benjamin
-------------- next part --------------
A non-text attachment was scrubbed...
Name: p.20080827
Type: application/octet-stream
Size: 38815 bytes
Desc: not available
URL: <http://gcc.gnu.org/pipermail/libstdc++/attachments/20080828/7764ea00/attachment.obj>