Add some information to Packaging cmake wiki

[Kevin Kofler]

Richard Shaw wrote:
> Hmm... I guess we shouldn't add it to the cmake macro then :) I
> usually wait and see if there's a problem first and then try that as
> the fix. I haven't had a situation where it gave me bad flags yet, but
> I did have a package that hard coded "Release" with bad flags (-O3
> etc..) so I had to patch around that one.

Yeah, some packages try to strip Release builds (e.g. through the -s flag), 
and -O3 is also semi-common.

KDE, on the other hand, enables some debugging code in RelWithDebInfo which 
we really don't want in shipped packages (only Release defines NDEBUG). The 
Release mode flags of course don't include -g, but the -g gets picked up 
from the Fedora optflags anyway.

        Kevin Kofler