Clean up after bad subprocesses exit

If the bundler dies during an exit and throws an error we
previously would not have the name of the file to clean up.

Change-Id: I07b6f8bdeba734054cac6f83f073e6c41ddc4a33
Better method of registering log transports

This means we no longer need a logger global variable.

Change-Id: Ib327da5069ec7a6ca11bd509ca14ee4d7ca91e26