Resynchronize the TeX docs with (a) the module docstring, and (b) my recent
fix to the code to make it behave like the module docstring.
diff --git a/Doc/lib/libcmd.tex b/Doc/lib/libcmd.tex
index 153d7a3..83e5ff8 100644
--- a/Doc/lib/libcmd.tex
+++ b/Doc/lib/libcmd.tex
@@ -43,9 +43,9 @@
 
 An interpreter instance will recognize a command name \samp{foo} if
 and only if it has a method \method{do_foo()}.  As a special case,
-a line containing only the character \character{?} is dispatched to
+a line beginning with the character \character{?} is dispatched to
 the method \method{do_help()}.  As another special case, a line
-containing only the character \character{!} is dispatched to the
+beginning with the character \character{!} is dispatched to the
 method \method{do_shell} (if such a method is defined).
 
 All subclasses of \class{Cmd} inherit a predefined \method{do_help}.