Migrating from Boost 1.35 to TR1

Just porting some stuff over to TR1, here some things that you need to take care of:

• For easy migration, prefer to use the boost/tr1/ headers, as they provide a fall-back to Boost if TR1 is not available.
• std::tr1::function has no empty () function, use if (function_object) instead.
• std::tr1::tuple has no get member function, use std::tr1::get<0> (tuple_instance) instead. For some reason or another, no ADL is possible here.
• boost::bind provides the placeholders _1, _2, etc., while std::tr1::bind doesn’t – I’d stick with boost::bind as the _1 placeholders are very convenient.
• There is no scoped_array, shared_array in <memory> – use Boost for this.