doc/go1.3.html: drop support for windows 2000
doc/go1.3.html: drop support for windows 2000

LGTM=bradfitz, alex.brainman
R=golang-codereviews, bradfitz, alex.brainman
CC=golang-codereviews
https://codereview.appspot.com/85190043

pombredanne/go-deleteme,pombredanne/go-deleteme,tv42/old-go,pombredanne/go-deleteme,pombredanne/go-deleteme,pombredanne/go-deleteme,tv42/old-go,tv42/old-go,tv42/old-go,tv42/old-go,tv42/old-go,tv42/old-go,pombredanne/go-deleteme,pombredanne/go-deleteme