refactored code - new API version, can output JSON

Second release of Application Skeleton.
Now callable from other code through API; now outputs JSON in addition to Shell, Swift, and Pegasus; other small changes.
See CHANGELOG for more details

first public release

This is the first public release for application skeletons - a tool to generate skeleton applications that mimic a real applications' parallel or distributed performance at a task (but not process) level. It can create bag-of-task,
(iterative) map-reduce, and (iterative) multistage workflow applications
This tools/concept allows computer scientists to focus on the system they are building; they can work with the simpler skeleton applications and be sure that their work will also be applicable to the real applications.