More ASN.1 definitions for Train Interface
Remove use of '§' in ASN.1 comments

* Needed for proper inclusion in latex document
Include ASN.1 for train interface in document. Define LaTeX style for ASN.1
Add "ASN.1 Primer" appendix. Improve Makefile. Introductory text to Train Interface
Improve content of ASN.1 Primer
Improve Train Interface description
Improve ASN.1 Primer text
Update PDF version