Sliding... for even worse abominations (b0.6)

For this update I've started working on a sliding feature. Essentially, it lets you automate sliding any audio effect/modulation parameter from one value to another in a set duration, back and forth. Here's a demo video of sorta how it works, with a lovely groan tube:

In the future, I'll open up the ability to change the easing transition and direction parameters.

There have also been a few QOL changes, namely key bindings. You can press Space to pause/play audio now, and the swap to Restart mode on this button is now Ctrl (meaning you can do Ctrl + Space to restart the audio). Record functionality has its own hotkeys: Shift+R to start/stop recording (a red recording dot will now show up at the top right), Shift+S to save the recording, and Shift+C to clear any recorded audio from the buffer. I also plan to have a Hotkeys tab to let you re-bind these in the future, and I'm likely going to remove the Record tab (or move the buttons somewhere else, as it really doesn't need its own tab at the moment).

Although not used yet in 0.6, I'll be adding a Help tab to explain modulation/sliding functionality as well as all of the hotkeys to help make it a bit less confusing to use.

Finally, number input boxes will now have their focus released after a new value is entered. Nothing big, but having the input box remain highlighted and focused after pressing Enter felt broken to me.