Fix file-size stats on OSX

Kernel makefiles that the stat on the system is GNU stat. GNU stat uses the "-c" option to specify format.
Darwin stat uses the "-f" option to specify format. This discrepency will cause kernel build breaks.
On my system, I symlink stat to GNU stat. This causes the "get-file-size" define
to fail.
The fix for this is to detect "gstat", aka GNU stat, and use that appropriately.

Change-Id: I987c155b7dc3ff14ffe6da40edf834ca34b7df75

Fix up the get-file-size function that was broken due to the prior commit that made it utilize gnu stat (gstat)

Change-Id: I24bba2bfcb509ad1ad76d2260eedd685ba45c393
Allow a device to generically define its own headers

We have a few cases of devices including specific versions of projects
just because of modified headers (msm_mdp.h comes to mind), and I just
had enough of ifdeffing header files for specific cases (the P990 needs
a lot of these).
Now... if a target defines a TARGET_SPECIFIC_HEADER_PATH, any headers in
there will take precedence over the standard ones; for example, on the
p990, I have

TARGET_SPECIFIC_HEADER_PATH := device/lge/p990/include

which makes, for example, the
device/lge/p990/include/hardware_legacy/AudioHardwareInterface.h be
used instead of
hardware/libhardware_legacy/include/hardware_legacy/AudioHardwareInterface.h
whenever a source file uses <hardware_legacy/AudioHardwareInterface.h>

Change-Id: I41b62668b60e3f62a6ebd3738d8d2675103a81e6a

build: fix target header overlay

LOCAL_C_INCLUDES as defined by the makefile should be put AFTER
the overlay includes so the overlay always takes precedence.

Change-Id: I489b2aab6dbacd9122d834f85e07b63ed1271f07
ota: Remove cruft we don't care about

Skip the date check (downgrade to your content), and don't include
recovery in otapackages.
5.0.0 update: We want the recovery patchstuff back
fix up ota_from_target_files symlink detection.
Add mka function

Credits:CM

https://github.com/CyanogenMod/android_build/commit/a254921e2cdc5128895e21b3720e7427d6cf4cb9

Signed-off-by: iceandfire <arhamjamal@gmail.com>