Fix some formatting errors, typos and other problems (#78)

Some notes:
- Removed a TODO note that was fixed in commit 43d9fbac.
- Removed a duplicate note about the '%l' time format in the changelog.
- Applied the following documentation fixes from Terrence J. Doyle:
  - https://www.mail-archive.com/ast-developers@lists.research.att.com/msg01852.html
  - https://www.mail-archive.com/ast-developers@lists.research.att.com/msg01856.html
- Fixed strange grammar in one of the error messages.
- Added missing options for rksh to the synopsis section.
- Applied a formatting fix from ksh93v- to the man page.
- Replaced a C99 line comment in src/lib/libast/comp/realpath.c with a
  proper comment that is valid in C89.
- Prioritize UTC over GMT in the documentation (missed by commit c9634e90).
- Add some extra information for 'ksh -R file' to the man page. This patch
  is from Red Hat: https://git.centos.org/rpms/ksh/blob/c8/f/SOURCES/ksh-20080202-manfix.patch

src/cmd/ksh93/tests/arrays.sh

@@ -663,8 +663,8 @@ arr5=(foo bar)
 [[ $(typeset -p arr5) == 'typeset -a arr5=(foo bar)' ]] || err_exit 'typeset expanding non-declaration aliases'
 
 typeset -A Foo
-Foo=( [a]=AA;[b]=BB)
-[[ ${Foo[a]} == AA ]] || err_exit 'Fooa[a] is {Foo[a]} not AA' 
+Foo=([a]=AA;[b]=BB)
+[[ ${Foo[a]} == AA ]] || err_exit 'Foo[a] is {Foo[a]} not AA'
 
 # ======
 # Crash when listing an indexed array

src/cmd/ksh93/tests/attributes.sh

@@ -447,7 +447,7 @@ typeset -l x=
 
 unset x
 typeset -L4 x=$'\001abcdef'
-[[ ${#x} == 5 ]] || err_exit "width of character '\01' is not zero" 
+[[ ${#x} == 5 ]] || err_exit "width of character '\001' is not zero"
 
 unset x
 typeset -L x=-1

src/cmd/ksh93/tests/builtins.sh

@@ -694,7 +694,7 @@ actual=$(
 expect='1'
 if [[ $actual != "$expect" ]]
 then
-    err_exit "I/O error not detected: expected $(printf %q "$expect"), got $(printf %q "$actual"))"
+    err_exit "I/O error not detected: expected $(printf %q "$expect"), got $(printf %q "$actual")"
 fi
 
 # ======
@@ -702,11 +702,11 @@ fi
 
 expect=$'0m00.0[0-9][0-9]s 0m00.0[0-9][0-9]s\n0m00.000s 0m00.000s'
 actual=$("$SHELL" -c times)
-[[ $actual == $expect ]] || err_exit "times output: expected $(printf %q "$expect"), got $(printf %q "$actual"))"
+[[ $actual == $expect ]] || err_exit "times output: expected $(printf %q "$expect"), got $(printf %q "$actual")"
 
 expect=$'*: times: too many operands'
 actual=$(set +x; eval 'times Extra Args' 2>&1)
-[[ $actual == $expect ]] || err_exit "times with args: expected $(printf %q "$expect"), got $(printf %q "$actual"))"
+[[ $actual == $expect ]] || err_exit "times with args: expected $(printf %q "$expect"), got $(printf %q "$actual")"
 
 # ======
 # 'whence' builtin

src/cmd/ksh93/tests/pty.sh

@@ -448,7 +448,7 @@ r echo repeat-3
 !
 
 # Following test is disabled because a bug in pty causes it to fail on too
-# many operating systems. Apparently pty doesn't handle SIGSTP correctly:
+# many operating systems. Apparently pty doesn't handle SIGTSTP correctly:
 # https://github.com/att/ast/issues/375
 # TODO: fix pty and re-enable this test.
 : <<\end_disabled