Add utility classes, migrated from ImageJ core

Migrated from:
https://github.com/imagej/imagej/tree/imagej-2.0.0-beta-7.9/core/core/src/main/java/imagej/util
Add non-image-specific services from ImageJ core

This includes the module and command frameworks, including widgets
(module preprocessing that handles inputs) and displays (module
postprocessing that handles outputs).

It also includes the menu, options, platform, script and tool services.
ContextCreationTest: expect new services, too
Remove imagej-isms from javadoc