Add basic grouping to Options

Add basic grouping to Options

- Add simple Options::addGroup() to create groups within an option,
  allowing out-of-order creation of options.  In the future, this can
  also be used for improved help output.
- Replace multiple Options objects in trajectory analysis runner with a
  single Options and groups within that container.  This is a
  significant step to make also this code use ICommandLineOptionsModule
  instead of a custom implementation.
- Remove complicated code with some dubious corner-case behavior from
  the command-line parsing code, now that all command-line options are
  in a single Options object.

addSubSection() in Options is now unused, and its general design does
not match that of the other Options code.  Will refactor and/or remove
it separately.

Change-Id: Ifaa28a210b46edc0a2b25e7e5c335f0708f532f8