changes until v0.83

CHANGELOG

• Renamed WIDTH, HEIGHT, CENTERX, CENTERY, MOUSEX, MOUSEY and ELAPSED to, respectively, W, H, CX, CY, MX, MY and T.
• round() now accept a 2nd param to precision. Example: round(PI, 3) == 3.142.
• Readd wave().
• Renamed seed() to rseed().
• Added iskeypressed().
• Removed colcirc() and colrect().
• Added pal().
• Removed getcolor().
• Renamed setvar() to def().
• Renamed setfps() to framerate().
• Added stat().
• Removed litecanvas() option pauseOnBlur.
• paint() now returns a ImageBitmap.

More details in https://litecanvas.js.org/about.html