help should accept -info . and -info .. arguments

[Gary Dixon]

The Multics help command has an -info BLOCK_NAME argument to select otherwise hidden info blocks (blocks that begin with an :[Info]: BLOCK_NAME: block divider) in an info segment. This -control_arg enables the developer to display subsystem request help blocks using the Multics help command (rather than having to enter the subsystem to use its help request).

The Multics help command correctly processes a BLOCK_NAME of:

? name of the ssu_-provided request which summarizes request names

help mbuild.gi -info ?

>udd>m>gd>w>mbc>mbuild.gi.info  [Info]: ?   (10 lines in info)

2020-07-27  ?

Syntax:  ?

Function:  prints a list of requests available in this subsystem.

Notes:
There may be other requests available in the subsystem which are not
listed by this request.  Such requests may be listed using the request:
   list_requests -all

r 05:47 0.475 276

However, it currently fails to accept two other ssu-provided request names:

. display subsystem name and version
.. escape a command line to Multics command level.

help -mbuild.gi -info .
help: Specified control argument is not accepted. -mbuild.gi
r 05:47 0.048 2

help -mbuild.gi -info ..
help: Specified control argument is not accepted. -mbuild.gi
r 05:47 0.058 2

This ticket requests that the help command be enhanced to accept those two request names as acceptable operands of the help -info control argument.