build: 1/2 remove squisher

build: Pass OTAPACKAGE location to squisher

Pass the OTAPACKAGE location so we don't have to guess what
the package name will be. This fixes an issue when
BUILD_NUMBER is defined in an environment with automated
builds.

Change-Id: Iab18b541de37c99d237aabc3cb7b2e9ab076617b
Fix building when OUT_DIR is out of ANDROID_BUILD_TOP

This broke in http://review.cyanogenmod.com/#/c/23686/ / http://review.cyanogenmod.com/#/c/23687/

Change-Id: I9dc77a1fb465a30c833262ba3b1de3d2f0f968f0
envsetup: set OUT_DIR to an absolute path always

OUT_DIR was set to $(TOPDIR)out previously,
but $(TOPDIR) was null, so it was a relative path.
This broke releasetools, inline kernel building, etc
since they require absolute paths.
Fix it so that it is set to $(shell readlink -f .)/out
if $(TOPDIR) is null.

Also remove hacks which checked if (OUT_DIR) was out
and changed it to $(ANDROID_BUILD_TOP)/out to workaround
the aforementioned problem.

Change-Id: I459a3b1325a1bbea0565cd73f6acf160d4ed9b39
Load only the current product config makefile.

To reduce the start time.
With the change and previous change of doing clean step in only given paths,
start time of mm/mmm is reduced from ~5s to about 1s;
lunch time is reduced from ~40s to 3.5s.

Bug: 7186768,7169854
Change-Id: Ifd72ba1c6362a5e1125a23c505fd47947ab56675