Updated QuickStart links + a typo fix

QuickStart links pointed to 404s; also, “relatively links” → “relative links”
PVector additions with tests for p5 API parity [#1981]

fromAngle, heading, lerp, magSq, random2D, random3D, rotate, setMag
comment cleanup
turns out SVG child parsing added an extra child step between all elements
updated failing unit test
ignoring new ArrayList(<num>), since Processing does, too. Also updated test.
p.online no longer exists in P5 2.0
nuked.
emergency lint fix
Adding ability to listent to pointer events, useful for ProcessingJS development for Windows 8, Windows Phone, pointer-enabled browsers.

Simulates pointer events on the touch and mouse events on non-pointer enabled browsers.

Added examples for sketches implementing ProcessingJS.
Merge branch 'PointerEvents' of https://github.com/matthiasxc/processing-js into PointerEvents
Added examples tested on non-pointer browsers.