remove Message objects + rewrite server startup

Change-Id: Ide72fb915c3ca93c74edadd8952853508e677de7
Reviewed-on: https://forge.frm2.tum.de/review/19199
Tested-by: JenkinsCodeReview <bjoern_pedersen@frm2.tum.de>
Reviewed-by: Enrico Faulhaber <enrico.faulhaber@frm2.tum.de>

test/test_lib_enum.py

@@ -22,7 +22,8 @@
 """test Enum type."""
 
 import sys
-sys.path.insert(0, sys.path[0] + '/..')
+from os import path
+sys.path.insert(0, path.abspath(path.join(path.dirname(__file__), '..')))
 
 # no fixtures needed
 import pytest