VanirActions: Flush memory

Triggerable by touching memory tile

todo: add clear all apps to the function
      possibly hack an OOM event by
      dd if=/dev/zero of=junk bs=10MB count=200
      with the purpose of forcing memory lost from
      leaks to be returned (sooo dirty)

PS2: added icon to forgotten resolutions. opted for ; instead
     of && so any commands down the chain will still run if stopped.
     added pkill to systemUI.

PS3: fix icon. reformat scripting. reformat helper class to use string array in a loop instead of
     using cmdprocessor to exec a massive one-liner. change string name. test finalization and
     garbage collection. some minor cleanup.

PS4: fix potential issue with loop

PS5: run on separate thread than UI & clean up script. done.

PS11: Make use of existing shell script helper, CMDProcessor
      Don't remount /data rw, because it's already rw
      Restore previous drop_cache value after fiddling with it

PS12: Fix restoration

PS13: Clean imports

PS14: Do flushing in FlushMemory.java instead of helpers, and wait until AFTER gc/finalize before restoring drop_cache value
      use static final TAG for logging, and make execFlush private

PS15: correct return type

PS16: add missing declaration... herpderp

PS17: add DoubleTap helper to manhandle activity lifecycle.

PS18: more mutual exclusion for lifecycle manhandling, and make a few things global to prevent them getting killed when onResume returns

PS19: Made flushing synchronous so it finishes.
      Import sanatization.
      Display stdout and stderror for commands that fail.

PS20: Add toString() to CommandResult, and use IT instead of EasyPair

PS21: Remove redundant drop_cache writing
      Don't restart SystemUI
      Add click for memory tile that causes a flush

PS22: Make touch handler synchronous (hopefully to make it actually happen)
      Toast
      Optipng

PS29: Fix the dodo i did with my last PS

Change-Id: I09ff06d748b79911367a6f12814255a46eef3ebf
Merge "VanirActions: Flush memory" into jb42