* Song database and entity overhaul, part 1.
* Remove Songs table from a number of qeries and reports.
* Fix references to Songs table; rewrite StationMedia processing.
* Remove song reference in queue page.
* Allow custom log level via environment variable.
Some functionality of AzuraCast has always been intended for "Power Users", but seemingly no amount of warnings or labels will prevent users from discovering these features, misusing them, and either burdening our support channels or declaring AzuraCast to be "broken". With this update, new installations have some of these most dangerous settings (manual port assignments, manual directory selection, custom LS/Icecast config, etc.) disabled. They can easily be re-enabled by editing "azuracast.env" and turning them on, and will remain available for all previous users by default.
All core AzuraCast Docker images are now tagged with "latest" for rolling-release updates and "stable" for the latest stable version. Switching to release builds switches the images used for all AzuraCast components, yielding a much more stable interaction between components. As new releases are made, the "stable" versions of each image are updated in unison with each other.
