resolve/remove USAGE_LICENSE macros; remove repetitive (c) strings

This takes another small step towards disentangling the build
system from the old AT&T environment. The USAGE_LICENSE macros with
author and copyright information, which was formerly generated
dynamically for each file from a database, are eliminated and the
copyright/author information is instead inserted into the AST
getopt usage strings directly.

Repetitive license/copyright information is also removed from the
getopt strings in the builtin commands (src/lib/libcmd/*.c and
src/cmd/ksh93/data/builtins.c). There's no need to include 55
identical license/copyright strings in the ksh binary; one (in the
main ksh getopt string, shown by ksh --man) ought to be enough!
This makes the ksh binary about 10k smaller.

It does mean that something like 'enum --author', 'typeset
--license' or 'shift --copyright' will now not show those notices
for those builtins, but I doubt anyone will care.

src/lib/libcmd/dirname.c

@@ -30,7 +30,7 @@
 
 static const char usage[] =
 "[-?\n@(#)$Id: dirname (AT&T Research) 2009-01-31 $\n]"
-USAGE_LICENSE
+"[--catalog?" ERROR_CATALOG "]"
 "[+NAME?dirname - return directory portion of file name]"
 "[+DESCRIPTION?\bdirname\b treats \astring\a as a file name and returns "
 	"the name of the directory containing the file name by deleting "
@@ -55,7 +55,7 @@ USAGE_LICENSE
 "\nstring\n"
 "\n"
 "[+EXIT STATUS?]{"
-        "[+0?Successful Completion.]"
+        "[+0?Successful completion.]"
         "[+>0?An error occurred.]"
 "}"
 "[+SEE ALSO?\bbasename\b(1), \bgetconf\b(1), \bdirname\b(3), \bpathname\b(3)]"