Add ability to specify alternate LXC config template file.

Does not "stick" in images.

Either:
  * to the server as a whole with the -T option with docker -d
  * on a specific run with the -T option to docker run
  * during container build with DockerLxcTemplate in the
    directory along side Dockerfile
Fixed api_test
Fix so docker build with a LXC template does not pollute server runtime
Fixup after rebasing to make it compile/work again
go fmted
rebase fixup
post rebase fixups... again