test/zdtm: unify common code

This commit expands the success with lib/Makefile to the rest of
ztdm/Makefiles. In particular, it moves the common part to Makefile.inc
and let {lib,static,transition}/Makefile use it.

This results in:
 - dependencies being handled properly;
 - reduction of makefiles length due to unification;
 - possibly more proper dependencies and builds.

While at it, let's also:
 - make rules for criu-rtc.so silent;
 - set default CC=gcc;
 - remove duplicate -m32 from CFLAGS.

Signed-off-by: Kir Kolyshkin <kir@openvz.org>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>