Remove: version identifier and changelogs from source code files

[dennisguse]

Currently, the source files contain a changelog as well as version identifiers in their header.
Before using GIT (or other version control system), this is quite useful.
Using a VCS, however, complicates the workflow as the change

There are two options for solving this issue:

• move changelogs/version information into sparerate files (per tool?)
• remove changelog/version completely and use a the (A) commit ID or (B) add a release identifier (a separate file containing the release name + data).

In addition, I would recommend moving the authors also into a separate file (at least everybody except the initial author).