InputDeviceSetup: use 20% of list with for sliders

setSeperation length was hardcoded resulting in issues for
localised string (not enough room).
Limiting the size of the sliders minimises the change of
limited space for translated strings.
InputDeviceSetup: clean list on recreating device option list

Previous commit deleted this line by accident...
Allow plugins to recursivaly close via menus
Satfinder: Move NIM selection to main screen

Most credits should go to Huevos

In addition arrange recursive close when a service is selected from the
scan results screen and other small changes.
Focus on selected service when stop edit alternatives
Menu: use boundfunction from Tools
Merge remote-tracking branch 'pli/master'

Conflicts:
	lib/python/Plugins/SystemPlugins/Satfinder/plugin.py
	lib/python/Screens/Menu.py