Released first iteration of optional module installation, using Batch API to
    install modules.

  Finalized code structure for module selection task.
  Added capability to detect modules and module dependencies.
  Used Batch API to install modules
  Added scaffolding for optional module selection task.

by JamesAn: Expanded scaffolding with UI for the module selection task.
  Adds automatic module detection in module selection task.
  Adds links to project pages for modules not installed.
  Uses External Links in module selection task to handle project page links.
  Adds an empty second install task.
  Abstracts scaffolding to generate code to connect each install task to its
    corresponding Form API definition and submission handler.
  Abstracts components of the DSNF in module selection screen so a list of
    candidate modules is translated into a set of radio buttons filtered
    through the module detector.