* clarify extractstats
* remove 4/12 hour stats as it’s unnecessary clutter, and by default
there is only a 24 hours stats file so the sort order and the aggregate
stats are wrong anyway, and besides the RRD resolution is too low by
default. If users want this, they can add it properly now.
* make top N AS intervals configurable (see config.inc), and allow
separate top stats file to be used per interval (enables e.g. proper
weekly/monthly stats)
* add Terabyte formatting
sFlow and Netflow v9/v10 may provide VLAN information in flows, so
one can distinguish between different logical links on the same
physical connection (e.g. transit via private VLAN over IXP).
