Reformat the add_listform doc file in order to remove an HTML glitch.

Extend the add_listform interface so that the user can specify a printing
"consistency" for the block of list elements. Previously, it was just
assumed that the user always wanted (INCONSISTENT,0). This is the value
now specified in the various places where add_listform is used.

Typo correction.

Modify the add_listform function in line with a suggestion of Lockwood
Morris's to provide slightly more flexibility in the way that list forms
are pretty-printed. Previously, the format was fixed as
<left-delimiter> el1 <sep> <a space> el2 <sep> <a space> ...
Now, the spacing is more directly under user-control.

Huge number of check-ins, implementing change to .doc file syntax.
Now the rule for text within braces is that it appears as given, but
that braces must balance. If you want an unbalanced brace, you can use
\lbrace or \rbrace. No existing .doc file uses unbalanced braces.
Also, there is now no need to use \noindent. In fact, doing so
will get you a complaint from the parser. Similarly, use of \ or
{} characters outside of verbatim text blocks will cause griping.
All of the new files have been generated by a parse-then-print process
from the old files, and it's possible there are errors. If you ever
have a spare moment, casting your eye over a random selection of these
might help to find errors.

Fixes to existing docs.

New versions of docfiles.