Allow simple invocation of loadjs.ready

[W1zzardTPU]

Instead of loadjs.ready(['foo', 'bar'], { success: function() { } });

this can be used

loadjs.ready(['foo', 'bar'], function() { });

[amorey]

@W1zzardTPU Thanks for the PR. I think it will be useful to pass a callback function as an argument. Here are a couple of questions:

1. Should the callback function execute only on success? What happens on error?
2. Should loadjs() also accept a callback function as an argument?

[W1zzardTPU]

1) For simplicity I was thinking just execute on success, do nothing on error. If more control is needed, pass an array as currently supported. 2) I have no use for that functionality, but I can see how it could benefit other scenarios and it would make the API more uniform

[amorey]

Thanks for the clarification. Here are some modifications for your consideration: https://github.com/W1zzardTPU/loadjs/pull/1