Fix NPE + Add Extra infos

Hi Joe !
Thanks for the amazing work ;-) ! Plenty useful in my Te Araroa preparation !
I have just fixed a null reference on get_trail_links_ function (happens when trying to read YHA images from the website).
I have also added the extra info to the output.
Do not hesitate to come back to me if needed !
Thanks again for your job !
Julien