datum+misc: r5js.ast.Boolean. Use instead of r5js.DatumType.BOOLEAN where poss.
datum+runtime: remove r5js.Datum#isBoolean in favor of instanceof checks.
datum+misc: r5js.ast.Character. Use instead of r5js.DatumType.CHARACTER.
datum+runtime: remove r5js.Datum#isCharacter in favor of instanceof checks.
datum+misc: r5js.ast.Number. Use instead of r5js.DatumType.NUMBER where poss.