Test framework for TrajectoryAnalysisModules.

Test framework for TrajectoryAnalysisModules.

- Add a test fixture that makes it simple to test analysis tools that
  are implemented as TrajectoryAnalysisModule subclasses (moduletest.*).
- Add tests using the new fixture for most of the functionality of the
  Select module.
- Minor adjustment to reference data test fixture to make it more usable
  in this context.
- Move all dataset registration calls to trajectory analysis module
  constructors from initAnalysis().  Also moved static initialization of
  the datasets, in particular calls to setMultipoint().
  In addition to enabling the tests to access the datasets before any
  initialization of the module is done, this also makes the modules
  easier to use for other interfacing than the command-line runner.

Main part of #920, may need some additional features.

Change-Id: I67e123f8361fe7710e936d9b4a880e65a3dc89c5