Add support for Vue.js

I've got a branch started here https://github.com/segovia94/pdb/tree/feature/vue that currently has 3 example components. The first uses an inline template and is the bare minimum. The second uses an html template and loops through all blocks so that there can be multiple instances. The third is an implementation of the standard ToDo list from the vue.js examples.

There is also an option to enable development mode which will use the non-minified library so that it will work with Vue Devtools in Chrome.

I'm thinking of creating a fourth example that compiles a dist/ with webpack as an example of how to use components in .vue files.

I created a pull request to the github account https://github.com/mrjmd/pdb/pull/101.

In order to allow faster development I've broken out this request into its own module Decoupled Blocks: Vue.js. It doesn't appear that this really needs to be included in the core module.