Date Tools Plugin

I've created a datetools plugin that will be useful as soon as 0.9.13 is rolled out. It provides various common dates to be used in twig templates.

https://github.com/kalebheitzman/grav-plugin-datetools

I'll be adding more methods and documentation in the next 24-48 hours.

Ok, i'm going to finish up the new feature I was working on and get 0.9.13 out!

btw @kaleb, hop on our Gitter chat, it's easier: https://gitter.im/getgrav/grav