samsung_battery: Charge level interface

- defaults are stock currents
- now separate interfaces for ac and usb

(cherry picked from commit 4a988fb3fd163d0a2967d27ad1b9eecd89ad4fd7)

Conflicts:
	arch/arm/mach-exynos/Kconfig
	drivers/battery/samsung_battery.c
samsung_battery: Charge level interface v2

- added sysfs interface to ignore unstable power
- added sysfs interface to ignore margin

based on implementation of AndreiLux in Perseus kernel

(cherry picked from commit 2219d7566b92ddcd91d3ed1d9379797c5867e6a5)

Conflicts:
	drivers/battery/max77693_charger.c
samsung_battery: Charge level interface v2a

- bug fix for wrong if statements causing the settings to be reset

(cherry picked from commit 62aa7856536d13c7c6ff52fab75e9f3679b51bc5)