remove trueMain (it's not being called)
Merge pull request #97 from mcellis33/QOL

remove trueMain (it's not being called)
Don't require the VBoxManage tool if we're not going to do path translation.

In the future, perhaps we should rename the VirtualBox interface to something
more general -- PathTranslator? -- then have a no-op implementation as well as a
VBoxManage implementation.
Trim leading slashes off of container names we get from `docker inspect`.

Do so immediately after getting the slash-prepended name from Docker, rather
than ad-hoc later on.

For reasons I don't fully understand, un-normalized container lookups (GET
/containers//foo_bar/json) were failing when made over a unix socket, rather
than a TCP connection.  Maybe go-dockerclient is wiring up the HTTP client in a
way that does path normalization over TCP but not unix sockets?
Rip out dependency on virtualbox

We still do path translation when DOCKER_HOST is tcp://, but always use the home
directory guessing logic rather than try to determine where vagrant has mounted
things.  @iansmith tells me that we were always taking this codepath before,
because vboxmanage doesn't report useful information on NFS shares.