Placed GCD and LCM typdefs and declarations in integer_fwd.hpp inside namespace boost::integer (was in boost::math) and checked that expected tests pass (and expected fails fail).

(Major update to Boost.Integer docs available for review at https://dl.dropboxusercontent.com/u/43940943/modular-boost/libs/integer/index.html
on branch doc-revision).

include/boost/integer_fwd.hpp

@@ -159,6 +159,8 @@ template <static_min_max_unsigned_type Value1, static_min_max_unsigned_type Valu
     struct static_unsigned_max;
 
 
+namespace integer
+{
 //  From <boost/integer/common_factor_ct.hpp>
 
 #ifdef BOOST_NO_INTEGRAL_INT64_T
@@ -180,6 +182,7 @@ template < typename IntegerType >
 template < typename IntegerType >
     class lcm_evaluator;
 
+} // namespace integer
 
 }  // namespace boost