AOKPTorch : add support for using sysfs instead of camera HAL

using sysfs is cleaner and faster for most devices
also i have reused CM's config.xml template, thus devices that already had CM's overlay/packages/apps/Torch
can use it with AOKP's torch too

I would encourage all maintainers to switch to sysfs mode as it is a visibly faster toggling interface

this also lets those devices that do not have a working (or have a buggy) camera HAL to use the torch

PS3-PS6 : code cleanups and formattings (thanks to Jon for teaching me Android Code guidelines :) )

PS8: removed unused variables; handle on off switching with one method; propperly handle
     closure of BufferedWriter; Removed duplicated code; some other small refactorings
PS9: use write value pulled from config.xml
PS10: propperly track status
PS11: swap write value positions
PS12: fix build

Change-Id: I0b129b7168e819fb249fa8abf7a7eff39ebd6636
Signed-off-by: ChampionSwimmer <android@championswimmer.tk>