chore(grunt): wip, extracts html2js into tmp folder

this is the first step to bring theming support to our boilerplate
feat(theming-support): introduces built-with-theme task

it actually does the same as the build task currently, so it's WIP
feat(theming-support): implements theming support

doesn't cover css-theming. this one is next up
Merge pull request #43 from PascalPrecht/theming-support

Theming support