[Off-topic] Wrote the suppressing warnings for GCC section of boost wiki page on Warning Guidelines

[Patrick Horgan]

I added a section to the boost warnings guidelines page about 
suppressing warnings with GCC.  I think it's pretty good bringing 
together information I got on this list, from reading the source and 
from browsing through the documentation for various releases of GCC.  If 
anyone wants to check it for correctness I would be very appreciative.  
I would in particular like to thank Jonathan Wakely for his willingness 
to help and for the great help he gave me on this list.

https://svn.boost.org/trac/boost/wiki/Guidelines/WarningsGuidelines

If you scroll to the bottom directly you'll see the end of the section 
on suppressing GCC warnings.

Thank you,

Patrick