Flattened hierarchy of mainentry

This improves performances and allow us to get rid of the ```NestedWeights``` warning.
The main list now scrolls slightly faster.
I like to keep the Android default.
This can never be a big deal om large screens.
The other margin fixes are applied now (unless I missed something) and it looks indeed nicer and makes a little bit more room for the application / restriction names.
Thanks for bringing this to my attention!