All dependencies have been moved to the new "dep:x" and "x?/feature" syntax to remove the bloat from the docs.rs/crates.io/lib.rs feature panes.
Accordingly, this lets us break "rustls" and "native" out from annoying hybrids like "serenity-rustls" or "twilight-native" -- specify your library and your backend, and it should just work.
The complete list of features is now: driver, gateway, serenity, twilight, rustls, native, builtin-queue, simd-json, internals (plus "default" and "full-doc").
Adds support to the library for tokio 0.2 backward-compatibility. This should hopefully benefit, and prevent lavalink-rs from being blocked on this feature.
These can be reached using, e.g., `gateway-tokio-02`, `driver-tokio-02`, `serenity-rustls-tokio-02`, and `serenity-native-tokio-02` features.
Naturally, this requires some jiggering about with features and the underlying CI, which has been taken care of. Twilight can't be handled in this way, as their last tokio 0.2 version uses the deprecated Discord Gateway v6.
This implements a proof-of-concept for an improved audio frontend. The largest change is the introduction of events and event handling: both by time elapsed and by track events, such as ending or looping. Following on from this, the library now includes a basic, event-driven track queue system (which people seem to ask for unusually often). A new sample, `examples/13_voice_events`, demonstrates both the `TrackQueue` system and some basic events via the `~queue` and `~play_fade` commands.
Locks are removed from around the control of `Audio` objects, which should allow the backend to be moved to a more granular futures-based backend solution in a cleaner way.
