Imgur album support, only first pic. 

As mentiond in https://github.com/ubershmekel/redditp/issues/1 albums should not spam redditp. So this solution adds only the firs picture to redditp. 

A problem is that a imgur app ID is needed. Another problem is that the request to the imgur api is included in a copy of the addImageSlide() mehod. That makes the code a bit redundant.

Just have a look at it.