McHorse's McLib

This big update adds a lot of useful code (including WAV file parsing, loading and rendering), a handful of GUI element tweaks and new multi-skin features!

• Added multi-skin editor, which includes new options:
  • Scale - scales up and down a skin
  • Shift - moves around a skin on the canvas
  • Scale to largest - allows easily to scale to the largest multi-skin in the list
  • Color - allows to multiply every pixel by this color, allowing hue shifting grayscale textures
  • Pixelate - filter that allows to pixelate a texture
  • Erase - option that allows to erase everything below using the current skin's opaque pixels as erase mask
• Added list sorting to multi-skin
• Added an option to asynchronously load multi-skin skins (enabled by default)
• Added WAV parsing and waveform rendering
• Added favorite and recent color palette GUI elements to color picker
• Added arrow up and down keystrokes to increment and decrement, respectively, a value in trackpad fields (shift, ctrl and alt affect the value that is getting added or subtracted, suggested by Joziah2)
• Added an option to disable increment button on trackpad fields
• Fixed relative value editing of keyframes having horrible results
• Fixed crash when emptying the text field in texture picker (reported by Tossler)
• Fixed trackpad fields not indicating that value wasn't accepted after manually inputting out of range (reported by Tossler)
• Fixed alpha colors not showing transparency when borders are enabled
• Fixed dashboard not closing properly panels after switching to another GUI (instead of closing through Escape key) causing some panels to bug (reported by Chunk7)