mq: new commands qselect, qguard implement quilt-style guards for mq. guards allow to control whether patch can be pushed. if guard X is active and patch is guarded by +X (called "posative guard"), patch can be pushed. if patch is guarded by -X (called "nagative guard"), patch cannot be pushed and is skipped. use qguard to set/list guards on patches. use qselect to set/list active guards. also "qseries -v" prints guarded patches with "G" now.