Fix cygwin-gcc and cmake problems

Fixed warning in CMake
Fixed problem with tuples creation
Fixed problem of stream copy constructor usage

include/sqlpp11/insert_value_list.h

@@ -105,7 +105,7 @@ namespace sqlpp
 			insert_list_data_t(Assignments... assignments):
 				_assignments(assignments...),
 				_columns({assignments._lhs}...),
-				_values({assignments._rhs}...)
+				_values(assignments._rhs...)
 				{}
 
 			insert_list_data_t(const insert_list_data_t&) = default;