cleanup commit for trigger processing:

cleanup commit for trigger processing:
- remove the DPkg::NoConfTriggers - absolutely useless as we need
  TriggersPending already so we can use --no-triggers.
- remove the Immediate-option from the example, it doesn't help much.
- UnpackCritical uses DepUnPackPre with a D (on simple letter...)
- the "smart" optimisation to skip A was not so smart - revert.