Ref. #448

- in journey test, remove @Ignores so that test runs exercise all tests.
- increase the verbosity of test logging to aide in seeing progress as
  tests are un@Ignored and solved.
- saving scripts used to make changes to all exercises.  These are the
  start of a library of scripts making such changes easier.
- make Gradle output more CI-friendly.

With exercism/exercism.io@54e1df3, we can now gather exercises into a
subdirectory. By separating the language track files from the
configuration and management files, it is easier to read the project.

- move gradle config under "exercises" too as it would make a mess
  otherwise.

The tests assume that the Deque class is implemented with generics.

The example implementation keeps track of a circular head Element.

Completes one task in https://github.com/exercism/xjava/issues/3.