This updates livesplit-core which brings a variety of performance
improvements:

- The Layout State is now being reused and thus most frames don't
  require any heap allocations anymore. However we still serialize
  everything over into a JSON string for now, which puts a lot of
  garbage on the JS heap.
  LiveSplit/livesplit-core#334

- The frequent performance.now() calls we do, first lookup up the window
  and performance object every time. This tripled the amount of calls we
  do over into JavaScript, with each call into JavaScript being quite
  expensive in Chrome.
  LiveSplit/livesplit-core#335

- By introducing a timer snapshot mechanism we further reduce the calls
  to performance.now() to a single time.
  LiveSplit/livesplit-core#339

- Rust 1.44 regressed the performance of 128-bit integer multiplications
  by accident. Those are used for hashing the comparisons when looking
  up the times for a comparison, which is something we do very
  frequently. We however don't have many comparisons, so a simple Vec
  that we loop through is a bit faster, even in native code, and quite a
  bit faster in the web, because of the Rust 1.44 regression.
  LiveSplit/livesplit-core#338

- We delay registering the Gamepad Hook Interval until the first gamepad
  button is registered. Most people won't use a gamepad, so the interval
  just waits cpu time for no reason.
  LiveSplit/livesplit-core#340

- Runs now support custom variables that are key value pairs that either the
  user can specify in the run editor or are provided by a script like an auto
  splitter. [#201](#201)
- There is now an option in the run editor to generate a comparison based on a
  user specified goal time. This uses the same algorithm as the `Balanced PB`
  comparison but with the time specified instead of the personal best.
  [#209](#209)
- Images internally are now stored as is without being reencoded as Base64 which
  was done before in order to make it easier for the web LiveSplit One to
  display them. [#227](#227)
- The Splits.io API is now available under the optional `networking` feature.
  [#236](#236)
- All key value based components share the same component state type now.
  [#257](#257)
- The crate now properly supports `wasm-bindgen` and `WASI`.
  [#263](#263)
- There is now a dedicated component for displaying the comparison's segment
  time. [#264](#264)
- Compiling the crate without `std` is now supported. Most features are not
  supported at this time though.
  [#270](#270)
- [`Splitterino`](https://github.com/prefixaut/splitterino) splits can now be
  parsed. [#276](#276)
- The `Timer` component can now show a segment timer instead.
  [#288](#288)
- Gamepads are now supported on the web.
  [#310](#310)
- The underlying "skill curve" that the `Balanced PB` samples is now exposed in
  the API. [#330](#330)
- The layout states can now be updated, which means almost all of the
  allocations can be reused from the previous frame. This is a lot faster.
  [#334](#334)
- In order to calculate a layout state, the timer now provides a snapshot
  mechanism that ensures that the layout state gets calculated at a fixed point
  in time. [#339](#339)
- Text shaping is now done via `rustybuzz` which is a port of `harfbuzz`.
  [#378](#378)
- Custom fonts are now supported.
  [#385](#385)
- The renderer is not based on meshes anymore that are suitable for rendering
  with a 3D graphics API. Instead the renderer is now based on paths, which are
  suitable for rendering with a 2D graphics API such as Direct2D, Skia, HTML
  Canvas, and many more. The software renderer is now based on `tiny-skia` which
  is so fast that it actually outperforms any other rendering and is the
  recommended way to render.
  [#408](#408)
- Remove support for parsing `worstrun` splits. `worstrun` doesn't support
  splits anymore, so `livesplit-core` doesn't need to keep its parsing support.
  [#411](#411)
- Remove support for parsing `Llanfair 2` splits. `Llanfair 2` was never
  publicly available and is now deleted entirely.
  [#420](#420)
- Hotkeys are now supported on macOS.
  [#422](#422)
- The renderer is now based on two layers. A bottom layer that rarely needs to
  be rerendered and the top layer that needs to be rerendered on every frame.
  Additionally the renderer is now a scene manager which manages a scene that an
  actual rendering backend can then render out.
  [#430](#430)
- The hotkeys are now based on the [UI Events KeyboardEvent code
  Values](https://www.w3.org/TR/uievents-code/) web standard.
  [#440](#440)
- Timing is now based on `CLOCK_BOOTTIME` on Linux and `CLOCK_MONOTONIC` on
  macOS and iOS. This ensures that all platforms keep tracking time while the
  operating system is in a suspended state.
  [#445](#445)
- Segment time columns are now formatted as segment times.
  [#448](#448)
- Hotkeys can now be resolved to the US keyboard layout.
  [#452](#452)
- They hotkeys are now based on `keydown` instead of `keypress` in the web.
  `keydown` handles all keys whereas `keypress` only handles visual keys and is
  also deprecated. [#455](#455)
- Hotkeys can now be resolved to the user's keyboard layout on both Windows and
  macOS. [#459](#459) and
  [#460](#460)
- The `time` crate is now used instead of `chrono` for keeping track of time.
  [#462](#462)
- The scene manager now caches a lot more information. This improves the
  performance a lot as it does not need to reshape the text on every frame
  anymore, which is a very expensive operation.
  [#466](#466) and
  [#467](#467)
- The hotkeys on Linux are now based on `evdev`, which means Wayland is now
  supported. Additionally the hotkeys are not consuming the key press anymore.
  [#474](#474)
- When holding down a key, the hotkey doesn't repeat anymore on Linux, macOS and
  WebAssembly. The problem still occurs on Windows at this time.
  [#475](#475) and
  [#476](#476)