The function sprintf is marked deprecated with the latest Clang version.
Move from sprintf to snprintf. Define and use buffer size.
Check the return value in a function where this is important.

The latest version of our formating rules is applied to all header and source
files as well as to the macros using clang-format 11.0.

The class FairLogger is  meanwhile only a wrapper around the Logger class,
so use the Logger directly. This also helps to reduce many warnings when
using the Eclipse IDE.

Apply code formatting to all source/header files and root macros.

This version is an exact copy of the last revision of the trunk branch
of the old SVN repository of CbmRoor at
https://subversion.gsi.de/cbmsoft/cbmroot/trunk
The old SVN repository will still be available for read access.