Fix crashes on missing config

We now merge user config with bootstrap config ensuring all configuratio
options are set even if not in configuratatin. Allowing us to add new
configuration options, without needing for users to touch their existing
configuration.

All default values are still written to user config when ever CFG.save
is called, which means when you change your output/input/source models
and configuration is missing, instead of just adding the configuration
needed for that particular module, it'll save full config to file.
Don't really think that is a bug, but might be something to fix later on
with maybe parameter to 'save'. Which would load user config, merge it
with 'save' argument level and save user config. But unless someone is
bothered by it, I won't do it.

This commit fixes #1