trivial adjustments to enable warning-free compilation with gcc -Wall -W -Werror

[SVN r32364]

include/boost/detail/utf8_codecvt_facet.hpp

@@ -162,7 +162,7 @@ protected:
     virtual std::codecvt_base::result do_unshift(
         std::mbstate_t&,
         char * from,
-        char * to,
+        char * /*to*/,
         char * & next
     ) const 
     {

utf8_codecvt_facet.cpp

@@ -32,7 +32,7 @@ BOOST_UTF8_BEGIN_NAMESPACE
 
 // Translate incoming UTF-8 into UCS-4
 std::codecvt_base::result utf8_codecvt_facet::do_in(
-    std::mbstate_t& state, 
+    std::mbstate_t& /*state*/, 
     const char * from,
     const char * from_end, 
     const char * & from_next,
@@ -109,7 +109,7 @@ std::codecvt_base::result utf8_codecvt_facet::do_in(
 }
 
 std::codecvt_base::result utf8_codecvt_facet::do_out(
-    std::mbstate_t& state, 
+    std::mbstate_t& /*state*/, 
     const wchar_t *   from,
     const wchar_t * from_end, 
     const wchar_t * & from_next,