Releases 27

Add _isa tags to all build requires. Remove unused patch munge-correct-service-name.patch, upstream fixed. Update and add check-key-exists.patch back. Revert back to default CFLAGS. _GNU_SOURCE not needed any more.
Add _isa tags to all build requires. Remove unused patch munge-correct-service-name.patch, upstream fixed. Update and add check-key-exists.patch back. Revert back to default CFLAGS. _GNU_SOURCE not needed any more.