mkapush: updates

  -Will now build installed-file-list if not
  present. It's a horrible implementation, but
  it's the only way I see to do it atm.

  -Remounts system

  -Stops/starts the shell if it's pushing
  SystemUI or to /system/framework.

Signed-off-by: KhasMek <Boushh@gmail.com>
Revert "Load only the current product config makefile."

This reverts commit 54fa8c3ff9b1f0f1b0b9c551be864f1b7378c7fc.

Conflicts:
	core/product_config.mk

Change-Id: Ia942d826eae08429d91bbfbb6c43b1cdd78563f7