[REFACTOR] renamed SarosNet class

The name was not that good. It failed to actually describe the
purpose of that class.

Change-Id: I2407c73f6b3c9b8d61f4a8fd10ebbc21dd3d5eb9
Reviewed-on: http://saros-build.imp.fu-berlin.de/gerrit/1352
Tested-by: Jenkins CI
Reviewed-by: Stefan Rossbach <srossbach@arcor.de>