- bunch of spec tweaks, cleanups + corrections:
      - shorten rpm-build filelist a bit with glob use, reorder for saner grouping
      - missing isa in popt version dependency
      - only add rpmdb_foo symlinks for actually relevant db_* utils
      - drop no longer necessary file-devel dependency from rpm-devel
      - drop sqlite backend build-conditional
      - preliminaries for moving from db4 to libdb
    - use gnupg2 for signing as that's more likely to be installed by default