http, ipOps, listop, and match. This is mainly merging the best documentation
from the module source and scripting.xml into the module, with the aim of
making the source code the canonical source for module documentation.
Attached corrects answerFetcher[types.TXT]() in dns.lua which inserts
v.data into answers only if v.domain is present - I believe the test
should be for v.data. This was preventing TXT answers from being
returned from dns.query() with the retAll option.
