Moved most components of the library to iterators:: namespace.

This change excludes boost:: and boost::detail:: namespaces from ADL for unqualified function calls (e.g. algorithms). This reduces the possibility of name clashes with other libraries and user's code. One of the effects should be fixing test failures on gcc 4.2 and 4.4 due to clashed with Boost.TypeTraits.

Also some of the functions marked with inline keyword.

include/boost/iterator/interoperable.hpp

@@ -14,8 +14,8 @@
 
 # include <boost/iterator/detail/config_def.hpp> // must appear last
 
-namespace boost
-{
+namespace boost {
+namespace iterators {
 
   //
   // Meta function that determines whether two
@@ -27,7 +27,7 @@ namespace boost
   // standards requirements on constant/mutable container
   // iterators (23.1 [lib.container.requirements]).
   //
-  // For compilers that don't support is_convertible 
+  // For compilers that don't support is_convertible
   // is_interoperable gives false positives. See comments
   // on operator implementation for consequences.
   //
@@ -40,9 +40,13 @@ namespace boost
           is_convertible< A, B >
         , is_convertible< B, A > >
 # endif
-  { 
+  {
   };
 
+} // namespace iterators
+
+using iterators::is_interoperable;
+
 } // namespace boost
 
 # include <boost/iterator/detail/config_undef.hpp>