Better handling of master branch builds
Better handling of master branch builds

* Build the master branch to the `master` subdirectory on the Docker container
* Add special handling for the `baseurl` config setting, as this is the only setting we need to change for the master builds
* Move the legacy case (deploying to the `documentation` subfolder) to the end of the build script (so it's easier to remove it)

codeship/documentation,codeship/documentation,mlocher/documentation,mlocher/documentation,codeship/documentation,mlocher/documentation,codeship/documentation,mlocher/documentation