Horizontal and vertical navigation ok. closes #374 

I have added a new branch with the navigation working stable. Some changes are:

- Removed the ScrollView ( in theory scrollviews doesn't work good together with ListViews). I added a drag-animation effect.
- Optimised a bit and organised code in ReportsFragment and ReportsPaperFragments.
- Changed the moment to load/draw data to the end of navigation movement. In my opinion is better for performance and better for stop the data loading op if the user scrolls fast. 

I have changed many things and I have introduced errors in alignment, clicks, etc. I'll go for them in next PR (#401). 

Fixes #374 
I was using Xamarin Android Player as simulator, it have only 16 and 19 APIs. I'll change back.