use os.path.samefile instead of string comparison
no need to perform recursive call strategy here
just try to load stash files whichever the file is exists or not
catch only CommandError, to avoid pylint warning
split CleanupInstance functionality to interface method and concreat method, to avoid pylint warning
improve error handling of StartInstance. I don't like to change the traceback of actual exception by re-throwing error with exception object argumented
/proc/self/cgroup may contain blank line, so filter to exclude it
stylefix quote
stylefix quote
pass instance object to _SpawnLXC instead of instance.name
Introduce hvparam lxc_wait_timeout for LXCHypervisor

This parameter specifies the seconds to wait until LXC
container's state changed to RUNNING.
show messages to notice that there is another log file from LXC container when starting instance failed