Note a TODO and cope with some valgrind chatter.
Reworked ignoring of cruft lines.

Moved cruft-filtering to byline()'s processing of raw input.  Deal
with the known bug after first 100 errors, make it possible to
recognise the end of a block of cruft either by its last line or the
first line after it, add recognition of some new kinds of cruft.
Handle source-of-uninitialized-value blocks.

Similar to address blocks, these qualify some other issue.
Also ignore stray output from cfengine itself.
Cope with "(below main)" as function identification.
Cope with a few more quirks.