fix simple popups with more than one custom button - check for the PopupButton.CUSTOM flag within item.type and not a strict equality between PopupButton.CUSTOM and the item.type

So the callback on this works...

PopupManager.instance.showSimple("Choose!", "Mode select", [
	{ type:PopupButton.CUSTOM, text:'Custom 1' },
	{ type:PopupButton.CUSTOM + 1, text:'Custom 2' }
], handler);

...

function handler(flag) {
	trace(flag==PopupButton.CUSTOM);
	trace(flag==PopupButton.CUSTOM+1);
}
Merge pull request #78 from mikedotalmond/custom-popup-handlers

Fix click handler on simple popups with more than one custom button....