cgroup_test: Add a test for freezer subsystem

1. Confirm process's default state in cgroup.
2. Confirm process's state in cgroup after freeze it.
3. Confirm process's state in cgroup after thaw it.

Signed-off-by: Li Yang <liyang.fnst@cn.fujitsu.com>
cgroup_test: Add a test for devices subsystem

1.Confirm if file cannot be created in desired device if
  this device was set to access deny by cgroup
2.Confirm if file can be created in desired device if
  this device was set to access allow by cgroup

Signed-off-by: Li Yang <liyang.fnst@cn.fujitsu.com>
client.tests: small fix for cpuflags

fixs:
    1. fix module import error
    2. correct src dir

Signed-off-by: Xu Tian <xutian@redhat.com>
Merge pull request #28 from xutian/fix_cpuflags_test

client.tests: small fix for cpuflags
cgroup_test: Check libcgroup-tool and environment before starting test

Signed-off-by: Li Yang <liyang.fnst@cn.fujitsu.com>
Merge pull request #27 from liyangfnst/cgclear_fix

cgroup_test: Check libcgroup-tool before starting test
Merge pull request #25 from liyangfnst/device_access

cgroup_test: Add a test for devices subsystem
cgroup_test: Add a test for memory resource control

1.Set limit memory to 60M
2.Execute a process in cgroup, malloc 50M, and confirm
  the memory information in cgroup
3.Execute a process in cgroup, malloc 70M, and confirm
  the memory information in cgroup

Signed-off-by: Li Yang <liyang.fnst@cn.fujitsu.com>