This patch simplifies pie build. Main change is replaces explicit rules by
implicit which reduces Makefile size and makes it more readable.

Notes:
1) intermediate build files are preserved.
2) Both blobs are linked with util-net.o. Restorer blob doesn't require it,
but this allows to avoid explicit rule for it.

v3:
1) Fixed parasite build.
2) Fixed blobs deps - %.bin and %.bin.o can now be build in parallel.
3) Updated restorer link: restorer is not linked with util-net.o anymore.
Signed-off-by: Stanislav Kinsbursky <skinsbursky@openvz.org>
Looks-good-to: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>