Added Javadoc comments and fixed warnings in ChecksimRunner and Submission

Signed-off-by: Matthew Heon <matthew.heon@gmail.com>
Changes to Maven project to produce executable jar without dependencies

Signed-off-by: Matthew Heon <matthew.heon@gmail.com>
Ensure all submissions processed are unique

Done without using Java Sets as the interface is too limiting in many cases.
Instead, add invariant that only unique elements are added to the list.

Signed-off-by: Matthew Heon <matthew.heon@gmail.com>
Simplify hashCode in Submission

Signed-off-by: Matthew Heon <matthew.heon@gmail.com>
Smplify PreprocessSubmissions

Make tests accurate even if preprocessed submissions list has different element
ordering than original.

Signed-off-by: Matthew Heon <matthew.heon@gmail.com>