Work on #838 - Smoother scrolling - parent view

Applied view holder pattern for smoother scrolling and less allocations/GCs
Work on #838 - Smoother scrolling - Dimmable Adapter

View holder pattern in DimmableAdapter
Work on #838 - Smoother scrolling - OnOffActionRow
Work on #838 - Smoother scrolling - Toggleable Rows

View holder pattern for toggle buttons
Work on #838 - Smoother Scrolling - 1 Column

Expensive row height adaption only necessary when more than one column is rendered
Work on #838 - Smoother scrolling - Hardware acceleration

Enable hardware acceleration on supported devices
Merge branch '838-scrolling-performance' of git://github.com/mamohr/andFHEM into mamohr-838-scrolling-performance
#838 Refactor GenericDeviceOverviewViewHolder
Reformat code
Merge branch 'mamohr-838-scrolling-performance'