ct: return an error if we can't enter into CT

Signed-off-by: Andrey Vagin <avagin@openvz.org>
ct: return an error if execve fails

Signed-off-by: Andrey Vagin <avagin@openvz.org>
test: set descriptor and log level for the libct log engine

Signed-off-by: Andrey Vagin <avagin@openvz.org>
make: clean all libraries

Signed-off-by: Andrey Vagin <avagin@openvz.org>
go: add SetLSMLabel

Signed-off-by: Andrey Vagin <avagin@openvz.org>
test: make host mounts as slaves in a test mntns

We don't want propagate test mounts into the host mntns.
test: rework test loging functions

Signed-off-by: Andrey Vagin <avagin@openvz.org>
go: add EnterExecve
Dockerfile: add libselinux1-dev and libapparmor-dev
test/vz_enter: typo fix
Merge pull request #26 from avagin/xemul

ct: return an error if execve fails