adding Photos++ 3.55

This is a request to add Photos++ 3.55. This 3.55 contains patches provided by the authors for 3.54 which were related to compatibility with gcc 4.80+. This request is a replacement of the closed request for the Photos++ 3.54. This request is being made with the agreement of the Gen-conveners and is linked to a request that will be added to CMSSW in the next few minutes.