sweep2dim: reduce/raise kcal via sweep2sleep gestures

User configurable left->right swipe (brighten) power
sysfs paths:
/sys/module/sweep2wake/parameters/s2d_enabled
/sys/module/sweep2wake/parameters/up_kcal
/sys/module/sweep2wake/parameters/down_kcal

User must disable s2w/s2s while using. Great for insta-privacy if you set the up/down_kcal to 255 or higher :D
Disable sweep2wake:
echo "0" /sys/android_touch/sweep2wake
s2d: send kcal through new function
also turn off display if kcal is <= 0
s2d: Don't send kcal if we're turning off display, or if we're max.
s2d: Record original kcal, if it's max, do not update.
s2d: assign to sysfs in android_touch + cleanup

Conflicts:
	drivers/input/touchscreen/sweep2wake.c
	ramdisk/init.furnace.sh
s2d: Update kcal to 255/255/255 if we're going down
s2d: dont flag the kcal boost if we're writing it later on anyway
ramdisk: Adjust kcal_up/down values

73 is the best 'int' value we can drop 3 times before the kcal_min limit.