(1) validate textOutline, zIndex;
(2) validate uniform units on fontSize;
(3) add or update tests for invalid color, extent, fontSize, lineHeight, origin, padding, textOutline, and zIndex;
(4) better separate validation of styles from reporting results for invalid style values;
(5) add ability to return valid, interned values from style validation processing;
(6) genericize error reporting;
(7) add --treat-foreign-as error|warning|info|allow option;
(8) update MD document;