Log domains can be used to identify the source of log messages, such as
the test being run or the helper library.

v2: Add separate domains for different parts of the helper library and
    use an empty default domain for applications.
    Expand the log output to include the process name and the log level
    of the message in addition to the domain and pid.
    Print the expanded message only for warning and debug messages.

v3: check for glibc before using program_invocation_short_name

Signed-off-by: Thomas Wood <thomas.wood@intel.com>