any reason why `Sequence` does not implement `Iter...

# announcements

[Andrew Gazelka]

any reason why Sequence does not implement Iterable? It is annoying to have to have two extension functions to support things which have a forEach method.

[serebit]

https://stackoverflow.com/questions/35629159/kotlins-iterable-and-sequence-look-exactly-same-why-are-two-types-required/35630670#35630670

[serebit]

To quote: The key difference lies in the semantics and the implementation of the stdlib extension functions for Iterable<T> and Sequence<T>.