[allocator.requirements] Add linebreak hints

Partially addresses #693.

Author: tkoeppe

source/lib-intro.tex

@@ -2000,7 +2000,7 @@
   \tcode{true_type} only if the expression \tcode{a1 == a2} is guaranteed
     to be \tcode{true} for any two (possibly \tcode{const}) values
     \tcode{a1}, \tcode{a2} of type \tcode{X}.   &
-  \tcode{is_empty<X>::type}       \\
+  \tcode{is_empty<X>::\brk{}type}       \\
 
 \end{libreqtab4d}
 
@@ -2029,7 +2029,7 @@
 Note B:
 If \tcode{X::propagate_on_container_copy_assignment::value} is \tcode{true},
 \tcode{X} shall satisfy the
-\tcode{CopyAssignable} requirements (Table~\ref{tab:copyassignable})
+\tcode{CopyAssign\-able} requirements (Table~\ref{tab:copyassignable})
 and the copy operation shall not throw exceptions.
 If \tcode{X::propagate_on_container_move_assignment::value} is \tcode{true},
 \tcode{X} shall satisfy the