correct behavior of `toString`
correct behavior of `toString`

... on signals, should say '<Signal>', not '<Stream>'
rgrempel/core,eeue56/core,bradurani/core,simonh1000/core,vilterp/core,ThomasWeiser/core,simonh1000/core,suryagaddipati/core,laszlopandy/core,rick68/core,alexiamcdonald/elm-core,Dandandan/core,eeue56/core,Pisys/core,suryagaddipati/core,isaacsanders/core,bradurani/core,vilterp/core,rgrempel/core,isaacsanders/core,colinmccabe/core,ThomasWeiser/core,rick68/core,Pisys/core,martinos/core,Dandandan/core,colinmccabe/core,laszlopandy/core,martinos/core,alexiamcdonald/elm-core