• rewrite manpages in proper mdoc

• rng-tools 2.x vs. rng-tools 5.x vs. rng-tools5 vs.
  rng-tools2 vs. rng-tools-debian mess (cf. #915689)

Old TODO from hmh’s rng-tools 2-unofficial-mt.14:

! do not try to use /dev/foo in VIAPadlock mode
  (initscript)

! find a way to waste less system time when VIA xstore
  does not return data.  Busy-loop option.  Nanosleep
  option (very nice to system, but only 68kbit/s on
  2.6).

* Maybe define NDEBUG to remove assert() from
  the packaged binary?

Stats:
 - detect/store overflow on stat counters?
 - stats: average only since last stat dump?
 - add system resource usage stats (CPUTIME, etc)

Ideas:
 - TCP/IP sink mode (multiple streams)
 - TCP/IP source mode, compatible with the above
 - Protect the above with good crypto (TLS).

Backburner:
 - i18n (including argp)
 - file input with deletion of used bits
