Add JOB_REGISTRATION_TIMEOUT and DEBUG builder options

Currently the JOB_REGISTRATION_TIMEOUT option can be used to set the timeout that the build agent has to register a build job in Redis. This needs to be configurable for the registration token as well otherwise the token will be invalid when attempting to register the build, even though it may be within the threshold set by JOB_REGISTRATION_TIMEOUT.

Add a DEBUG option to have verbose output of the builder image.