Introduce new setting in [dirs] section of deploy.conf: `state`.
Override this setting with `--state-dir` option (useful when running
deploy from source).

This dir is currently used to store snf-deploy's `snf_deploy_status`
file, that shows which components on which nodes have been
installed. Do not update this file if `--dry-run` is used.

Additionally introduce `--templates-dir` option that overrides
`template` setting in [dirs] section of `deploy.conf`.

Note that override options do not modify the configuration files.
Changes are performed in the execution context of each snf-deploy
command.

To run snf-deploy from source use:

$ python setup.py develop
$ snf-deploy keygen -c conf -t files -s /tmp
$ snf-deploy all --autoconf -c conf -t files -s /tmp

Add the above setting to snf-ci's schema files.

Update Copyright dates.

Signed-off-by: Dimitris Aragiorgis <dimara@grnet.gr>