fix for missing lxc-ps command in ocf:heartbeat:lxc

since beginning of 2014 the lxc-ps command isn't available anymore
(see:
 https://lists.linuxcontainers.org/pipermail/lxc-devel/2014-January/007433.html)
so it is using now lxc-info to determine the PID of a container and "ps"
to get the command name of it.
remove check for unused binary
re-add LXCpre1.0 logic

now the old behavior should still work if LXC in a version prior 1.0.0
is used
Merge pull request #519 from Savar/fix_ocf_heartbeat_lxc

fix for missing lxc-ps/lxc-version command in ocf:heartbeat:lxc with LXC >= 1.0.0