Simplify logic to use std::vector's .empty()

No need to muck about with iterators, adding a loop, and 2 function
calls to test for empty: it's a std::vector under the hood, so use
.empty(), and inline it.

autodoc/inc/ary_i/ci_text2.hxx

@@ -72,7 +72,7 @@ class DocuTex2
                             DYN DocuToken &     let_drToken );
 
     const TokenList &   Tokens() const          { return aTokens; }
-    bool                IsEmpty() const;
+    bool                IsEmpty() const         { return aTokens.empty(); }
     const String &      TextOfFirstToken() const;
 
     String &            Access_TextOfFirstToken();

autodoc/source/ary_i/kernel/ci_text2.cxx

@@ -77,18 +77,6 @@ DocuTex2::AddToken( DYN DocuToken & let_drToken )
     aTokens.push_back(&let_drToken);
 }
 
-bool
-DocuTex2::IsEmpty() const
-{
-    for ( ary::inf::DocuTex2::TokenList::const_iterator
-                iter = aTokens.begin();
-          iter != aTokens.end();
-        )
-    {
-        return false;
-    }
-    return true;
-}
 
 using csi::dsapi::DT_TextToken;