[Tools] Added aurora::downcast()
[Meta] Added file for variadic template metaprogramming
[Meta] Added aurora::foreach() for iteration through variadic parameter pack
[Meta] Made aurora::foreach() dynamic and stateful

Now it is possible to pass functors with template operator() or C++14 generic lambdas. In contrast to stateless classes with static apply() methods, functors can carry information about their context.
[Tools] Added aurora::typeIndex()
[Meta] Added aurora::Typelist