cmd/ht: add -full option to quick tests
cmd/ht: add -full option to quick tests

Quick tests should be quick (and not do unexpected stuff) so under normal
operation the Link, Latency and Resilience checking /which produce additional
requests) is suppressed.
Add a new flag -full to include Link, Latency and Resilience checks.
Do a bit more during resilience checking now it is off by default.
Also do one extra round with 8 concurrent requests inflight in Latency
checking.
Use practically nonsensical low limits in the latency check to force
output of the measrued latencies. This assues you never do 'productive'
website testing with quick and -full: A 'full quick' test is a manual
introspection of the system.

vdobler/ht,vdobler/ht,vdobler/ht,vdobler/ht