Added a config file to describe multiple jobs to run, and to provide
values for options not specified on command line.
In the config file, presets can be used to save duplication of rip
options common to multiple jobs.
In its current state, the worker thread will process jobs submitted to
gearman by one or more clients. All output from HandBrake is captured
and logged along with diagnostic output from the worker process. The
client process takes commandline arguments to run a single ripping task,
and waits for it to complete.
