Boost.Range merge from trunk to release.

This is motivated by the need to correct the istream_range, to correct the adaptors.hpp header file, and correct the return types of various range algorithms.

[SVN r61517]

include/boost/range/algorithm/remove_copy_if.hpp

@@ -31,7 +31,7 @@ namespace boost
     remove_copy_if(SinglePassRange& rng, OutputIterator out_it, Predicate pred)
     {
         boost::function_requires< SinglePassRangeConcept<SinglePassRange> >();
-		return std::remove_copy_if(boost::begin(rng), boost::end(rng), out_it, pred); 
+        return std::remove_copy_if(boost::begin(rng), boost::end(rng), out_it, pred); 
     }
 }