remove all references to gobType() from the decoder. Fixes issue 470.
remove all references to gobType() from the decoder.
Fixes issue 470.

R=rsc
CC=golang-dev
http://codereview.appspot.com/183074

tv42/old-go,apparentlymart/golang,dsriram/golang,h8liu/golang,bdwalton/debian-golang,tianon/debian-golang,dsriram/golang,h8liu/golang,gnanderson/go,gnanderson/go,nightlyone/golang,tv42/old-go,tianon/debian-golang,tv42/old-go,ssrl/go,gnanderson/go,pombredanne/go-deleteme,h8liu/golang,ssrl/go,pombredanne/go-deleteme,apparentlymart/golang,dsriram/golang,gnanderson/go,bdwalton/debian-golang,h8liu/golang,tv42/old-go,gnanderson/go,ssrl/go,ssrl/go,ssrl/go,tianon/debian-golang,h8liu/golang,ssrl/go,gnanderson/go,tv42/old-go,tianon/debian-golang,ssrl/go,tianon/debian-golang,tianon/debian-golang,tianon/debian-golang,bdwalton/debian-golang,nightlyone/golang,gnanderson/go,pombredanne/go-deleteme,apparentlymart/golang,apparentlymart/golang,tianon/debian-golang,bdwalton/debian-golang,bdwalton/debian-golang,pombredanne/go-deleteme,pombredanne/go-deleteme,h8liu/golang,h8liu/golang,apparentlymart/golang,dsriram/golang,pombredanne/go-deleteme,bdwalton/debian-golang,dsriram/golang,dsriram/golang,apparentlymart/golang,nightlyone/golang,nightlyone/golang,tv42/old-go,bdwalton/debian-golang,tv42/old-go,pombredanne/go-deleteme,nightlyone/golang,bdwalton/debian-golang,nightlyone/golang,apparentlymart/golang,dsriram/golang,nightlyone/golang