working on UI/IO stuff

- defaultFont,defaultLineHeight,defaultTextPadding
- keyHandle() constructor for adding keys to a list of things to handle
key presses
- UIbutton() constructor for making buttons (unfinished)
- fill() and stroke() methods added to Circle() and Box() (old
rendering.js functions depreciated)
- clearLast() method added to box (untested) (old rendering.js function
depreciated)
- inputHandler() renamed to keyHandler(), user-defined input() renamed
to key()