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/cmd/ksh93/bltins/enum.c

@@ -22,7 +22,7 @@
 
 static const char enum_usage[] =
 "[-?@(#)$Id: enum (AT&T Research) 2008-01-08 $\n]"
-USAGE_LICENSE
+"[--catalog?" ERROR_CATALOG "]"
 "[+NAME?enum - create an enumeration type]"
 "[+DESCRIPTION?\benum\b is a declaration command that creates an enumeration "
     "type \atypename\a that can only store any one of the values in the indexed "
@@ -43,7 +43,7 @@ USAGE_LICENSE
 
 static const char enum_type[] =
 "[-1c?\n@(#)$Id: type (AT&T Labs Research) 2008-01-08 $\n]"
-USAGE_LICENSE
+"[--catalog?" ERROR_CATALOG "]"
 "[+NAME?\f?\f - create an instance of type \b\f?\f\b]"
 "[+DESCRIPTION?\b\f?\f\b creates a variable for each \aname\a with "
     "enumeration type \b\f?\f\b where \b\f?\f\b is a type that has been "