Rename list.xml to device_list.xml

This was done mainly for readability.
Rename item.xml to device_item.xml

This was done mainly for readability.
Fix indentation.
Create dummy fragment for routed devices.
Update gradle commands.
Start routed device fragment only if clicked on a router item.
Implement back navigation.
Take out comment.
Correct back navigation from action bar.
Set action bar title in fragment.
Use updated library.

Only the manifest data where changed.
Use devscan library which is no longer executable.
Take out proguard for release build.

It just doesn't work with gson.
Take out debug print.