`lxc-info -iH` to retrieve IP address was not available in early LXC
development but was there at LXC 1.0. Because we've bumped our minimum
LXC requirement to v1.0 recently, we can simplify the IP retrieval
process and also get rid of the `dnsmasq` fallback.
Subprocessed being interrupted resulted in it looking
like those commands were executing successfully but with
zero output. Interrupting the sudo prompt would result
in any command running in sudo returning nothing and looking
like it had succeeded. There was some clean up code in
the lxc provider that nuked vagrant container state in
the .vagrant directory if it looked like the container no
longer existed based on the result of lxc-ls. Interrupting
this check resulted in it looking like the container not
existing, resulting in the provider code nuking the lxc dir
in .vagrant. Voila
* for lxc to 1.0.0 using constant Vagrant::LXC::Driver::DEFAULT_CONTAINERS_PATH
* change method Vagrant::LXC::Driver::CLI#version to call lxc-create if lxc-version command not exists (to lxc version 1.0.0)