config: Switch logging to new config system
spotify: Rename 'proxy_host' to 'proxy_hostname' for consistency
spotify: Switch to new config system
Merge pull request #389 from jodal/feature/spotify-using-config

Update Spotify backend to use config
main: Make it more obvious what helper to use for exiting
Merge pull request #388 from adamcik/feature/config-logging

config: Switch logging to new config system
spotify: Fix errors after switch to new config system
main: Make sure 'extensions' is defined before 'finally' block is executed
config: Create global proxy config section.