piuparts.py: run adequate if installed (Closes: 703902)

* piuparts.py: Run adequate (if installed) after installation test.
  New options --no-adequate and --fail-if-inadequate. (Closes: #703902)
* debian/control: add adequate to piuparts' recommends.
piuparts-report: add templates for known_problems/inadequate_issue and inadequate_error.
adequate changelog re-ordering.
p.conf: add [sid-nodoc] section

Signed-off-by: Andreas Beckmann <anbe@debian.org>