1.  "braces" -> "brackets" when referring to [ and ].
1.  "braces" -> "brackets" when referring to [ and ].

PR:		19894
Submitted by:	Tony Finch <dot@dotat.at>

2.   "brackets" -> "angle brackets" when referring to < and >.

3.  Clean up the bit about creating the usage() message.  After clarifying a
couple of points the sentence became rather long, and rather poor English, so
it was converted to a enumerated list instead.

parts 1, 2, 3:
Reviewed by:	sheldonh

jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase