#428 Make rail diagrams project a Maven project

After getting this into your development environment, if the problems stick around, do the following:

• Select common.asciidoc and common.raildiagrams projects, right click them, and choose 'Maven' -> 'Update project...'. Click 'Select All' to select all projects. Select only 'Refresh workspace resources from local filesystem' and 'Clean projects' at the bottom. 'Update dependencies' should always be selected. Click 'OK'.
• If needed, rebuild all projects.

Closes #428 (closed)