Fix "build: display the full path of the installed libs, to allow copy paste"

When OUT_DIR is not "out", it'll show the wrong path, as the out dir
won't be under ANDROID_BUILD_TOP

This fixes commit 80970297312c426f326284e81869db8a2cf8a487.

Change-Id: Ie8610ec5e1e4ae570a64fba9168a686bfe929961
build: kernel: remove hard coded darwin toolchain.

* Use latest kernel toolchain from $(ARM_EABI_TOOLCHAIN) variable.

Change-Id: I3b43408937dd5f193fcba19c034f868272de8963
unpackbootimg: add a target specifically for unpackbootimg.
for some reason, and I am guessing this is a bug in the Android build, I can no longer run the following:
make -j32 out/host/darwin-x86/bin/unpackbootimg

It works if the build has been built, but not if it is clean. Somewhere within the bowels of AOSP
something broken in 4.1.2.

Change-Id: I4f8c434f3fce9ddaee4f54febba02efac07a31a3
fix sdk target with absolute OUT_DIR

Add / to atree's search path.

since I459a3b13 OUT_DIR is absolute. atree uses these variables and
due to "-I ." tries to resolve these paths as relative paths.

Change-Id: Ic9fbc84acdd9f438dfc813f6496e2c5e0d761976