oops
style fix

- Move % operators to end of line
- Replace single quotes to double quotes
Added function _IsInstanceAlive to LXCHypervisor

This function returns True if instance pointed by instance_name
is running.
GetInstanceInfo was changed to use this function.
Added functions to LXCHypervisor that are used to manage instance stash file

Instance stash file is used to keep informations that needs to complete
instance destruction during instance life.
should be instance method
Change LXCHypervisor to respect its currently belonging cgroup hierarchy

- Added _GetCurrentCgroupSubsysGroups to read current process cgroup information
  from /proc/self/cgroup.
- Change _GetCgroupInstanceSubsysDir and _GetCgroupInstanceValue to use return
  value of _GetCurrentCgroupSubsysGroups as the base hierarchy of cgroup.
s/Returns/Return
make sure that the CleanupInstance called correctly during process after resource allocated
Move codes to run lxc-start from StartInstance to _SpawnLXC in LXCHypervisor

Move functionality to spwan LXC container into _SpawnLXC.
Also _SpwanLXC will ensure that the daemonized LXC container process
running correctly by using lxc-wait.
Added function _EnsureCgroupMounts which ensures all required cgroup
subsystems are mounted

Cgroup mount requirements are not only from LXCHypervisor.
Cgroup subsystems in LXC config file should mounted before running lxc-start.