Some users like to have their project in ~/code/mgmt/ for example, but
this is not compatible with a $GOPATH which is elsewhere. This isn't a
problem unless you need vendored directories in ~/code/mgmt/vendor/
which doesn't work because ~/code/mgmt/ isn't in $GOPATH. With this
symlink and the provided ~/bin/go wrapper, vendored directories work
exactly as expected, and we also get a local $GOPATH pointing to the
same thing. Since $GOPATH must have a src/ dir, and vendor/ must NOT,
then we symlink the two together accordingly.
An important part of this is that those who like to put everything in
$GOPATH won't be affected by any of this!
