Report that on Android, applications are fullscreen only and dont handle their own minimization

As a result, the minimization button, that is used on Maemo 5 and enabled by default will not be shown on Android.
Only stop location if location provider is available
Get path to themes folder from the paths module, clean-up path handling
Add a constant for default theme id
Move some theme related code from icons to theme
Use alternative color name as QML looks like it can't handle gray23
Try to get icon from default theme if not found in the given theme
Initial theme switching buttons