rewrite lxc-ps

rewrite lxc-ps

Use bash instead of perl; eliminates final lxc dependency on perl
(beneficial for minimal operating system environments).

Modify the cgroup search to only use hierarchies that contain one
or more subsystems. When searching, if a hierarchy contains the
'ns' subsystem, do not append '/lxc' to the parent cgroup.

Maintain column spacing. Expand container name column as necessary.
Properly handle spaces in 'ps' output that are not field separators
(for example, try 'lxc-ps -o pid,args').

Fix file mode in repository.

Signed-off-by: David Ward <david.ward@ll.mit.edu>
Signed-off-by: Daniel Lezcano <dlezcano@fr.ibm.com>