[m-rev.] for review: add a "suggested replacement" arg to obsolete pragmas

[Zoltan Somogyi]

For review by anyone.

The main change in {Log,DIFF}.obs adds the optional new argument
to obsolete pragmas. Once that diff reaches the rotds and is installed
on each of our systems, the second diff can be committed.

Note that the library has a bunch of old obsolete declarations.
I propose that

- for obsolete declarations that precede 14.01, we delete the
  obsolete predicates;
- whereas for obsolete declarations that post-date 14.01,
  we add a second argument.

Zoltan.
-------------- next part --------------
A non-text attachment was scrubbed...
Name: Log.obs2
Type: application/octet-stream
Size: 1558 bytes
Desc: not available
URL: <http://lists.mercurylang.org/archives/reviews/attachments/20190908/0996255c/attachment-0004.obj>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: DIFF.obs2
Type: application/octet-stream
Size: 30805 bytes
Desc: not available
URL: <http://lists.mercurylang.org/archives/reviews/attachments/20190908/0996255c/attachment-0005.obj>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: Log.obs
Type: application/octet-stream
Size: 1894 bytes
Desc: not available
URL: <http://lists.mercurylang.org/archives/reviews/attachments/20190908/0996255c/attachment-0006.obj>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: DIFF.obs
Type: application/octet-stream
Size: 55069 bytes
Desc: not available
URL: <http://lists.mercurylang.org/archives/reviews/attachments/20190908/0996255c/attachment-0007.obj>