typeset: add error msgs for incompatible options; improve usage msg

This adds informative error messages if incompatible options are
given. It also documents the exclusive -m, -n and -T options on
separate usage lines, as was already done with -f. The usage
message for incompatible options now looks something like this:

| $ ksh -c 'typeset -L10 -F -f -i foo'
| ksh: typeset: -i/-F/-E/-X cannot be used with -L/-R/-Z
| ksh: typeset: -f cannot be used with other options
| Usage: typeset [-bflmnprstuxACHS] [-a[type]] [-i[base]] [-E[n]]
|                [-F[n]] [-L[n]] [-M[mapping]] [-R[n]] [-X[n]]
|                [-h string] [-T[tname]] [-Z[n]] [name[=value]...]
|    Or: typeset -f [name...]
|    Or: typeset -m [name=name...]
|    Or: typeset -n [name=name...]
|    Or: typeset -T [tname[=(type definition)]...]
|  Help: typeset [ --help | --man ] 2>&1

(see also the previous commit, e21a053e)

Unfortunately the first "Usage" line has some redundancies with the
"Or:" lines showing separate usages. It doesn't seem to be possible
to avoid this; it's a flaw in how libast generates everything
(usage, help, manual) from one huge getopt(3) string. I still think
the three added "Or:" lines are an improvement as it wasn't
previously shown that these options need to be used on their own.

src/cmd/ksh93/bltins/typeset.c: b_typeset():
- Instead of only showing a generic usage message, add an
  informative error message if incompatible options were given.
- Conflicting options detection was failing because NV_LJUST and
  NV_EXPNOTE have the same bitmask value. Use a new 'isadjust'
  flag for -L/-R/-Z to remember if one of these was set.
- Detect conflict between -L/-R/-Z and a float option, not just -i.

src/cmd/ksh93/include/name.h, src/cmd/ksh93/data/msg.c:
- Add the two new error messages for incompatible options.

src/cmd/ksh93/data/builtins.c: sh_opttypeset[]:
- Add a space after 'float' in in "[+float?\btypeset -lE\b]" as
  this makes 'float' appear on its own line, improving formatting.
- Show -m, -n, -T on separate usage lines like -f, as none of these
  can be combined with other options.
- Remove "cannot be combined with other options" from -m and -n
  descriptions, as that should now be clear from the separate usage
  lines -- and even if not, the error message is now informative.

src/cmd/ksh93/sh.1, src/cmd/ksh93/COMPATIBILITY:
- Update.

src/cmd/ksh93/tests/types.sh:
- Remove obsolete test: 'typeset -RF' is no longer accepted.
  (It crashed in 93u+, so this is not an incompatibility...)

Resolves: https://github.com/ksh93/ksh/issues/48

src/cmd/ksh93/sh.1

@@ -7799,13 +7799,30 @@ cannot be exported.
 .PD
 .PP
 The
-.B \-i
-attribute cannot be specified along with
+.BR \-i ,
+.BR \-F ,
+.BR \-E ,
+and
+.B \-X
+options cannot be specified along with
 .BR \-R ,
 .BR \-L ,
-.BR \-Z ,
 or
-.BR \-f .
+.BR \-Z .
+The
+.B \-b
+option cannot be specified along with
+.BR \-L ,
+.BR \-u ,
+or
+.BR \-l .
+The
+.BR \-f ,
+.BR \-m ,
+.BR \-n ,
+and
+.B \-T
+options cannot be used together with any other option.
 .PP
 Using
 .B \+