Missing 'width' option check

[ali997]

When 'callback' option was missing script was ignoring 'width' option.

This wont work:

$.farbtastic("#color", {width: 250});

This will:

$.farbtastic("#color", {callback: function(){}, width: 250});

Proposed fix will work for now but to avoid any future problems i think there should be something like:

typeof callback === 'function'

[mattfarina]

This should be handled differently. If there is no callback property than one should be defined rather than redefining options.

[ali997]

In my case i have to initialize script with empty callback, set color and then link to callback. There is no way to set starting color if i don't use input field and i have to initialize with options because you can't set width otherwise. Maybe there should be a color option then?