vendor: only vendor on emitted binaries

Moves the vendor/ directory to cmd/vendor. Vendored binaries are built
from cmd/, which is backed by symlinks pointing back to repo root.

build.ps1

@@ -0,0 +1,46 @@
+$ORG_PATH="github.com/coreos"
+$REPO_PATH="$ORG_PATH/etcd"
+$PWD = $((Get-Item -Path ".\" -Verbose).FullName)
+
+# rebuild symlinks
+echo "Rebuilding symlinks"
+git ls-files -s cmd | select-string -pattern 120000 | ForEach {
+	$l = $_.ToString()
+	$lnkname = $l.Split('	')[1]
+	$target = "$(git log -p HEAD -- $lnkname | select -last 2 | select -first 1)"
+	$target = $target.SubString(1,$target.Length-1).Replace("/","\")
+	$lnkname = $lnkname.Replace("/","\")
+
+	$terms = $lnkname.Split("\")
+	$dirname = $terms[0..($terms.length-2)] -join "\"
+	
+	$lnkname = "$PWD\$lnkname"
+	$targetAbs = "$((Get-Item -Path "$dirname\$target").FullName)"
+	$targetAbs = $targetAbs.Replace("/", "\")
+	if (test-path -pathtype container "$targetAbs") {
+		# rd so deleting junction doesn't take files with it
+		cmd /c rd "$lnkname"
+		cmd /c del /A /F "$lnkname"
+		cmd /c mklink /J "$lnkname" "$targetAbs"
+	} else {
+		cmd /c del /A /F "$lnkname"
+		cmd /c mklink /H "$lnkname" "$targetAbs"
+	}
+}
+
+if (-not $env:GOPATH) {
+	$orgpath="$PWD\gopath\src\" + $ORG_PATH.Replace("/", "\")
+	cmd /c rd "$orgpath\etcd"
+	cmd /c del "$orgpath"
+	cmd /c mkdir "$orgpath"
+	cmd /c mklink /J "$orgpath\etcd" "$PWD"
+	$env:GOPATH = "$PWD\gopath"
+}
+
+# Static compilation is useful when etcd is run in a container
+$env:CGO_ENABLED = 0
+$env:GO15VENDOREXPERIMENT = 1
+# TODO: Get the GIT_SHA argument to work for `etcd --version` style commands.
+$GIT_SHA="$(git rev-parse --short HEAD)"
+go build -a -installsuffix cgo -ldflags "-s -X $REPO_PATH/version.GitSHA=$GIT_SHA" -o bin\etcd.exe "$REPO_PATH\cmd"
+go build -a -installsuffix cgo -ldflags "-s" -o bin\etcdctl.exe "$REPO_PATH\cmd\etcdctl"