Some layout fixes

I've fixed some smaller layout issues:
- the navigation drawer item layout (record_home_navigation.xml) was way to complicated: I removed some useless layout-tags
- impoved IGF-Griditem layout: optimized the structure and moved the "bar" (the dark stripe with the title and all) to an extra layout file for reusability as this is used in list mode and grid mode
- fixed the gridview selector, this was gone with the switch to AppCompat, now there is a selector again, for Android 5+ there is a nice ripple effect