Fold subj2html.pl into emp2html.pl
Tighten up emp2html's info reference recognition

Combine the two loops looking for \*QNAME\*U and "info NAME" into one.
Recognize "info NAME" only with the closing '"' to be present.

No change with current info sources.
Don't put broken links in HTML info pages

Pass the valid info page names to emp2html.pl, and convert only valid
references to links there.
Fix read beyond end of conditional argument on missing operand

nstr_parse_val() interprets argument "" as (empty) identifier, then
returns a pointer right beyond the end of the string.

The argument points into player->argbuf[].  If another argument
follows the conditional, it gets appended to the conditional.  Else,
whatever's left there from previous commands gets appended.  If the
argument is at the very end of player->argbuf[], we parse beyond the
buffer, until we run into a syntax error, or a zero byte.

Since player->argbuf[] is followed by a bunch of pointers, a syntax
error is almost certain.  If we somehow manage to parse all the
pointers and player->lasttime, the runaway parse will end at
player->btused, because that's definitely zero when conditionals get
parsed.
Update change log again for 4.3.31