Branch graph, Version 0.55 - January 2014

1. Added the --draw-pipeline-graph opton. If set, the pipeline graph is produced in
.dot format.

2. Bug fix for when handling gkno specific arguments.
Branch graph, Version 0.57 - January 2014

1. If multiple tasks use the same input file and it doesn't exist, the warning
listing the missing files would include the same file multiple times. This is
fixed.
Branch graph, Version 0.58 - January 2014

1. Handled an error for poorly constructed pipeline configuration files. If an
argument required by a task is not set and instruction exist on how to construct
it, but the argument from which to build the name does not exist, and error is
thrown.