fixed includes/environment/nextPage()
fixed includes/environment/previousPage()
added initial support for spreads includes/environment
added arc() to includes/shape
added SINCOS_LENGTH, EPSILON, KAPPA to includes/constants
added PALETTE, PROMPT to includes/constants
refactored control -> ui
added runUpdateOnce() and runUpdateLoop() to includes/core.jsx
added runUpdateOnce() and runUpdateLoop() to pub.go() in includes/core
initial refactoring of control.jsx -> ui.jsx (untested)
further refactoring of ui.jsx - initial testing successful
refactored all ui examples initial tests successful
fixed constant b.PROMPT
added arc() modes to constants
b.arc() refactored & tested, seemlingy stable
cleaned up examples/demos/B09_user_interface and examples/ui
updated examples/shape/arc.jsx
added testArc to test/vertex-tests.jsx PASSED (NOTE: overlapping points bug)
fixed bugs in piechart.jsx