test: Include CheckManpage and CheckTexinfo in tests

[afh]

While debugging #2302 I noticed that CheckManpage.py and CheckTexinfo.py are not included in the test suite. I believe it is safe to include them even though they currently fail due to missing documentation for a few options and functions (see below), because the tests can only be run if ledger has been built with debug support as the CheckManpage.py and CheckTexinfo.py (via CheckOptions.py) use the ledger option --debug option.names parse true which only provides useful information with built with debug support.

@jwiegley from the top of your head could you provide a short description for the following missing option and function documentation (I'm happy to accept this here as a PR comment and take care of the manpage and texinfo syntax)?

$ python test/CheckManpage.py -l ./result-debug/bin/ledger -s .
Missing manpage option entries for:
  --sort-all

Missing manpage function entries for:
  averaged_lots
  clear_commodity
  commodity_price
  display_amount
  display_total
  lot_date
  lot_price
  lot_tag
  nail_down
  round
  rounded
  set_commodity_price
  top_amount
  unround
  unrounded

$ python test/CheckTexinfo.py -l ./result-debug/bin/ledger -s .
Missing texinfo option entries for:
  --sort-all

Missing texinfo function entries for:
  averaged_lots
  clear_commodity
  commodity_price
  lot_date
  lot_price
  lot_tag
  nail_down
  round
  rounded
  set_commodity_price
  top_amount
  unround
  unrounded