Extract uboot image creation from core/Makefile

http://memegenerator.net/instance/12495768

This change utilizes BOARD_CUSTOM_BOOTIMG_MK to extract out the Uboot boot and
recovery image generation out into it's own file (approx 130 lines).

This should:
    * Clean up the already huge Makefile and the keep ifdeffyness down
    * Make sure Uboot changes don't effect other builds
    * Extract a lot of code that is only for 3 devices

This depreciates BOARD_USES_UBOOT but BOARD_USES_UBOOT_MULTIIMAGE is still valid.

Boards who use uboot boot images should remove BOARD_USES_UBOOT and add
  BOARD_CUSTOM_BOOTIMG_MK := device/common/uboot-bootimg.mk
to their BoardConfig.mk
(location of the makefile is not finalized)

Change-Id: I90505a99cbcda11731ac3318cfe7f76b4bf6e1c7

Conflicts:
	core/Makefile
Fix up the recovery.fstab for adv recovery

Add options found in cm7 to allow for more complex recovery.fstabs with
multiple fstypes.

Change-Id: Id249c8f6766a1490a80fb3bd17bd7aa4e7dd9f2f

Conflicts:
	tools/releasetools/common.py
Include the primary bootloader and ramdisk in the BOOT/

This will copy over the primary bootloader (if it exists and defined)
over to the zip_root/BOOT.

This is required by encore as we need to make sure we have the correct
primary bootloader to go with the kernel.

Change-Id: I3fef417011b9c7a63109d10fc8e6794e58f73c31