Update kardianos/osext (ref #1272)

Godeps/Godeps.json

@@ -1,6 +1,6 @@
 {
 	"ImportPath": "github.com/syncthing/syncthing",
-	"GoVersion": "go1.5.1",
+	"GoVersion": "go1.5.2",
 	"Packages": [
 		"./cmd/..."
 	],
@@ -31,7 +31,7 @@
 		},
 		{
 			"ImportPath": "github.com/kardianos/osext",
-			"Rev": "345163ffe35aa66560a4cd7dddf00f3ae21c9fda"
+			"Rev": "431e263e413efe4446ede50cec4819b26659fbe7"
 		},
 		{
 			"ImportPath": "github.com/rcrowley/go-metrics",

Godeps/_workspace/src/github.com/kardianos/osext/osext.go

@@ -7,12 +7,18 @@ package osext
 
 import "path/filepath"
 
+var cx, ce = executableClean()
+
+func executableClean() (string, error) {
+	p, err := executable()
+	return filepath.Clean(p), err
+}
+
 // Executable returns an absolute path that can be used to
 // re-invoke the current program.
 // It may not be valid after the current program exits.
 func Executable() (string, error) {
-	p, err := executable()
-	return filepath.Clean(p), err
+	return cx, ce
 }
 
 // Returns same path as Executable, returns just the folder

Godeps/_workspace/src/github.com/kardianos/osext/osext_procfs.go

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build linux netbsd solaris dragonfly
+// +build linux netbsd solaris dragonfly freebsd
 
 package osext
 
@@ -27,6 +27,8 @@ func executable() (string, error) {
 		return execpath, nil
 	case "netbsd":
 		return os.Readlink("/proc/curproc/exe")
+	case "freebsd":
+		return os.Readlink("/proc/curproc/file")
 	case "dragonfly":
 		return os.Readlink("/proc/curproc/file")
 	case "solaris":