Added static option

I propose a `static` option for this plugin.
When set to true it makes the plugin behave much like the `mimosa-html-templates`.

I'm aware of `mimosa-client-jade-static`, but it saves html to individual files while I wanted something ready for single `require`. 

I don't see any testing example for mimosa modules, but I `npm link`ed it into my current project and verified it works.