fosdem-2014: Add a little demo to show the convergence concept

This is straight from qtquickcontrols examples and contains only a
phone optimized version.
fosdem-2014: Fix demo build
fosdem-2014: Use QFileSelector

For now we assume the file selector is desktop.
fosdem-2014: Move touch specific components to +touch
fosdem-2014: Move images to content/
fosdem-2014: Load platform specific URLs with an interceptor

QFileSelector is not flexible enough, we have to use the interceptor.
fosdem-2014: Rename project to appconvergence
fosdem-2014: Ignore built files