Arnau Siches

Clean `Duration` interface. And sanitise its arithmetics.

Repeating intervals

3

Add support for repeating intervals ``` Rnn/ R/ ``` Example: `R5/2008-03-01T13:00:00Z/P1Y2M10DT2H30M`

Check https://github.com/rails/rails/pull/16917#issuecomment-153409106

Hello, I've been reading the documentation specially the interop section as I'm just starting to play with Reason and I have to interact with Javascript a lot. I ended up...