adds compress iter ++ and removes ctor specs
adds compress iter ++ and removes ctor specs

I needn't specify the deletes and defaults, it doesn't gain me anything

ryanhaining/cppitertools,ryanhaining/cppitertools,jkhoogland/cppitertools,tempbottle/cppitertools,jkhoogland/cppitertools,tempbottle/cppitertools,jkhoogland/cppitertools,ryanhaining/cppitertools,tempbottle/cppitertools