Tool support

• JastAddGradle: a plugin for the Gradle build system, making it simple to build JastAdd projects.
• RagDoc Builder and RagDoc Viewer are JavaDoc-like documentation generator and viewers for JastAdd (work in progress).
• JastAddParser can be used to facilitate the use of the parser generator Beaver together with JastAdd.
• Syntax highlighting explains how to get syntax highlighting for JastAdd code.
• Tracing support for JastAdd.