Prepare a template file to contain client secrets

- The user is expected to copy "client_secrets.json.template" (remove
trailing ".template" from its name) and enter his client secrets in the
apropriate fields.
- .gitignore will ignore the newly created "client_secrets.json" so it
will not end up in the GIT repo by accident.
Merge branch 'master' of https://github.com/jonek/rap-oauth.git
Replace propagation of cid from Java to JS with clientId propagation

This removes the requirement to change the clientId in JS by hand or
have it contained there at all.
Update target platform and fix launch config