Move back to using Chrome on OSX closes #2043

This moves back to using Chrome on OSX but making it obvious that it's Chrome to avoid any user issues with running Chrome itself. This also includes a more general refactoring of the browser launching code, as it had gotten a little convoluted after various revisions. This should be a bit more maintainable and portable.
That's not surprising.  What I was saying is that I would be surprised if LanternUtils.getSystemResourceAsStream would ever return a result when LanternUtils.class.getResourceAsStream() doesn't.  That's because I expect LanternUtils was either loaded by the system classloader or a child of it, in which case it'll delegate to its parent.