Updated references and section document structure, as well as minor design aspects
Moved D.4..3 to new folder in reportUpdated references and section document structure, as well as minor design aspects
Revert "Moved D.4..3 to new folder in reportUpdated references and section document structure, as well as minor design aspects"

This reverts commit 31d35818ca0bda58e694333d64a41d9c27008f6e.
Merge pull request #183 from openETCS/Hazard-and-Risk

D-4-2-3  	Updated references and section document structure, as well as minor design changes