Fix more compiler warnings, typos and other minor issues (#260)

Many of these changes are minor typo fixes. The other changes
(which are mostly compiler warning fixes) are:

NEWS:
- The --globcasedetect shell option works on older Linux kernels
  when used with FAT32/VFAT file systems, so remove the note about
  it only working with 5.2+ kernels.

src/cmd/ksh93/COMPATIBILITY:
- Update the documentation on function scoping with an addition
  from ksh93v- (this does apply to ksh93u+).

src/cmd/ksh93/edit/emacs.c:
- Check for '_AST_ksh_release', not 'AST_ksh_release'.

src/cmd/INIT/mamake.c,
src/cmd/INIT/ratz.c,
src/cmd/INIT/release.c,
src/cmd/builtin/pty.c:
- Add more uses of UNREACHABLE() and noreturn, this time for the
  build system and pty.

src/cmd/builtin/pty.c,
src/cmd/builtin/array.c,
src/cmd/ksh93/sh/name.c,
src/cmd/ksh93/sh/nvtype.c,
src/cmd/ksh93/sh/suid_exec.c:
- Fix six -Wunused-variable warnings (the name.c nv_arrayptr()
  fixes are also in ksh93v-).
- Remove the unused 'tableval' function to fix a -Wunused-function
  warning.

src/cmd/ksh93/sh/lex.c:
- Remove unused 'SHOPT_DOS' code, which isn't enabled anywhere.
  https://github.com/att/ast/issues/272#issuecomment-354363112

src/cmd/ksh93/bltins/misc.c,
src/cmd/ksh93/bltins/trap.c,
src/cmd/ksh93/bltins/typeset.c:
- Add dictionary generator function declarations for former
  aliases that are now builtins (re: 1fbbeaa1, ef1621c1, 3ba4900e).
- For consistency with the rest of the codebase, use '(void)'
  instead of '()' for print_cpu_times.

src/cmd/ksh93/sh/init.c,
src/lib/libast/path/pathshell.c:
- Move the otherwise unused EXE macro to pathshell() and only
  search for 'sh.exe' on Windows.

src/cmd/ksh93/sh/xec.c,
src/lib/libast/include/ast.h:
- Add an empty definition for inline when compiling with C89.
  This allows the timeval_to_double() function to be inlined.

src/cmd/ksh93/include/shlex.h:
- Remove the unused 'PIPESYM2' macro.

src/cmd/ksh93/tests/pty.sh:
- Add '# err_exit #' to count the regression test added in
  commit 113a9392.

src/lib/libast/disc/sfdcdio.c:
- Move diordwr, dioread, diowrite and dioexcept behind
  '#ifdef F_DIOINFO' to fix one -Wunused-variable warning and
  multiple -Wunused-function warnings (sfdcdio() only uses these
  functions when F_DIOINFO is defined).

src/lib/libast/string/fmtdev.c:
- Fix two -Wimplicit-function-declaration warnings on Linux by
  including sys/sysmacros.h in fmtdev().

lib/package/ast-ksh.pkg

@@ -20,17 +20,17 @@ ast-ksh :PACKAGE: ksh93 libast libcmd libcoshell libsum libdll
 		these symlinks
 			/bin/ksh.exe => ksh93.exe
 			/usr/share/man/man1/ksh93.1 => ksh.1
-		are created.  This allows alternative ksh impelementations,
+		are created.  This allows alternative ksh implementations,
 		e.g., /bin/pdksh.exe, to be selected by changing the ksh.exe
 		and ksh.1 symbolic links.  In addition, ksh and ksh93 paths are
 		added to /etc/shells if not already present.
 		$()
 		Each builtin or special command accepts the --man and --html
-		options to list the man page on the standard error. The --???
+		options to show the man page on the standard error. The --???
 		option describes the self documenting options available to all
 		builtin and special commands.
 		$()
-		The stanadlone ksh is statically linked with the ast libcmd
+		The standlone ksh is statically linked with the ast libcmd
 		library which provides several builtin versions of /bin
 		commands. "builtin | grep /opt/ast/bin" lists the libcmd
 		builtins on the standard output. /opt/ast/bin/FOO accesses
@@ -55,12 +55,12 @@ ast-ksh :PACKAGE: ksh93 libast libcmd libcoshell libsum libdll
 		variables to convert. PATH is handled by cygwin so it is not
 		converted by the ast library.
 		$()
-		The astksh cygwin source package provides a bootstrap build
+		The ast-ksh cygwin source package provides a bootstrap build
 		environment that is not suited for an edit/build/debug cycle.
 		If you want to explore and modify the source then you should
 		install the (non-cygwinized) ast-base package which includes
 		AT&T nmake. With ast-base you will also be able to regenerate
-		the astksh cygwin source and binary packages.
+		the ast-ksh cygwin source and binary packages.
 		$()
 		For more information on ksh and other AT&T ast tools see
 		   http://www.research.att.com/sw/download/