[release-branch.go1.8] all: merge master into release-branch.go1.8

add1aac0 static: don't use the jQuery func for looking up based on hash
608c3b09 present: fix typo
0d047c8d cmd/godex: handle printing of type aliases
de557280 go/gcimporter15: update import/export to handle type aliases
5d76f8ce static: detect platform to hide/show unix/windows instructions

Change-Id: I327abdef58298a72d2c2cdcd24da6bfd096bd262