Update rpmbuild macro environment to make debug builds simpler

[danielhams]

It would nice that we can launch rpmbuild so that debug flags and no strip happens.

e.g.

rpmbuild --define 'sgugdebug 1' -ba something.spec --nocheck

This should

1. Tweak the default rpmbuild CFLAGS,CXXFLAGS to be -g -Og
2. Tweak the default rpmbuild LDFLAGS to be -Wl,-z,relro -Wl,-z,now (no RPATH)
3. Override __strip to be /bin/true

Not clear to me yet where these things should be tweaked or set.

[danielhams]

Edit: And bonus thought - it would be nice that any RPMs generated this way have some extension in the filename and/or version to indicate they are debug versions.

i.e. I'd like to be able to run and RPM query to see "ah crap, I've still got package X installed in debug"

Not sure that's possible while remaining compatible with correct versioning.

[danielhams]

First attempt with the changes listed above in 75e0eee in WNA.

We see if this needs further tweaking.