Various small fixes relative to the ingress paper.

[time.hms.members] Rephrased note.
[time.hms.overview] Removed redundant declaration of operator<<.
[time.hms.overview] Moved exposition-only data members to the bottom.

Author: jensmaurer

source/time.tex

@@ -747,8 +747,7 @@
 
     template<class charT, class traits, class Duration>
       basic_ostream<charT, traits>&
-        operator<<(basic_ostream<charT, traits>& os,
-                   const hh_mm_ss<Duration>& t);
+        operator<<(basic_ostream<charT, traits>& os, const hh_mm_ss<Duration>& t);
 
     // \ref{time.12}, 12/24 hour functions
     constexpr bool is_am(const hours& h) noexcept;
@@ -7797,15 +7796,7 @@
 
 \begin{codeblock}
 namespace std::chrono {
-  template <class Duration>
-  class hh_mm_ss
-  {
-    bool            is_neg;     // \expos
-    chrono::hours   h;          // \expos
-    chrono::minutes m;          // \expos
-    chrono::seconds s;          // \expos
-    precision       ss;         // \expos
-
+  template <class Duration> class hh_mm_ss {
   public:
     static unsigned constexpr fractional_width = @\seebelow@;
     using precision                            = @\seebelow@;
@@ -7821,11 +7812,14 @@
 
     constexpr explicit operator precision() const noexcept;
     constexpr precision to_duration() const noexcept;
-  };
 
-  template <class charT, class traits, class Duration>
-    basic_ostream<charT, traits>&
-      operator<<(basic_ostream<charT, traits>& os, hh_mm_ss<Duration> const& hms);
+  private:
+    bool            is_neg;     // \expos
+    chrono::hours   h;          // \expos
+    chrono::minutes m;          // \expos
+    chrono::seconds s;          // \expos
+    precision       ss;         // \expos
+  };
 }
 \end{codeblock}
 
@@ -7942,8 +7936,9 @@
   with \tcode{duration_cast<precision>(abs(d) - hours() - minutes() - seconds())}.
 \end{itemize}
 \begin{note}
-When \tcode{precision} is \tcode{seconds} with integral representation,
-\tcode{subseconds()} always returns \tcode{0s}.
+When \tcode{precision::rep} is integral and
+\tcode{precision::period} is \tcode{ratio<1>},
+\tcode{subseconds()} always returns a value equal to \tcode{0s}.
 \end{note}
 
 \pnum