This replaces the api export tables with updated versions, and inserts
comments for all "undocumented" items. The slow work of documented them
is left for later ;)
lxml does some formatting changes that are not significant for lxml processing,
but generate spurious difference in the diff (namely: ulinks become one-line,
and double quotes are used instead of single quotes for element attribute
values). This should be a one-time thing: subsequent renegeration should be
idempotent with regards to this.