Fixed possible ReferenceError in ArtJs.log

Checking `if (console)` will result in ReferenceError in environments (browsers) that don't have built-in console object. So it should be either `if (window.console)` which works for browsers or `if (typeof console !== "undefined")` or even `if (typeof console === "object")`.
Merge pull request #1 from kukawski/patch-1

Fixed possible ReferenceError in ArtJs.log