debugdeltachain: add a parameter to display all info
This will be useful with the next changeset that change the defaul output to display the minimum amount of information.
debug-delta-chain: actually skip unrequested computation
Doing quick test on mozilla-unified show we can run up to 2× faster by skipping
some of these computation.
debug-delta-chain: add options to control what we compute
Currently this mostly controls what we display, but actual computation saving
will come soon.