zdtm: execute tests on non C/R kernel (v2)

* add exclude list. Tests from this list are executed only on C/R kernels
* check that a version of a kernel is greater than 3.7

Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>