changes for detecting and building for clang/binutils elf

and minor fixes:
 . add ack/clean target to lib, 'unify' clean target
 . add includes as library dependency
 . mk: exclude warning options clang doesn't have in non-gcc
 . set -e in lib/*.sh build files
 . clang compile error circumvention (disable NOASSERTS for release builds)

tools/chrootmake.sh

@@ -8,7 +8,7 @@ then	make $@
 	exit $?
 fi
 
-make NOASSERTS=yes world
+make world
 cd tools 
 rm revision
 rm /boot/image/*