just prototype

This isn't intended to be merged, just to get on the same page on preprocessing stuff. Here's my attempt to implement outletting & iterating over stuff on slide with customizeble delimiters. 
See small [demo](http://sudodoki.github.io/cleaver/#5). 
There's also a matter to address on how to apply hooks to this kind of things (maybe, separate templates for outletted/iterated parts should be used or some callback/API provided to be able to modify text before it's getting into generated presenation - I mostly see this as a handy thing for themes).