Added support for drawing rgba transp colors

Also added small idea bout cap and joinstyles for lines...
Added support for drawing subpixel line thickness

Also interpixel thickness precision
Also support for line outlinewidth which previously didnt work

Still: polygons and line outlines are filled with the scanline algorithm
which currently doesnt do any antialiasing...
Almost fixed scanline fill and circles with fill

I say almost bc on rare occasion wont fill one line, prob cus of special
case in line intersection algo.
Also, for circles leaves gap in outline if outline is thick and becomes
very thick and ugly without antialiasing

So next:
Fix scanline fill algorithm to support antialiasing
Add multiline join rules
Add line stipple patterns
Add arc drawing
Add path drawing
Add circle ellipse support, and square/rectangle drawing
Add image
Add layered image support (multiple images that are drawn on
independently, can be shift their draw order, and are only combined when
rendering the final image)