Streamline console logging behavior.

[fschmenger]

Currently we have a bunch of components, which make use of console.warn and console.error statements. As a consequence the no-console es-lint rule, which is recommend by the vue-cli templates, is globally disabled.

Therefore I proposed the following as a comment within #312:
We should consider pooling all wegue logging operations into a dedicated logger module and then use the eslint-disable directive there locally. Subsequently the no-console rule could be enabled on the global level.