Fixing case of absolute symlinks

Note, for the sake of sharing via VCS absolute symlinks don't
tend to work so they should be avoided.
diff --git a/path/path.go b/path/path.go
index b939bea..0c3cee1 100644
--- a/path/path.go
+++ b/path/path.go
@@ -91,7 +91,11 @@
 			return gopath, nil
 		}
 
-		gopath = filepath.Join(filepath.Dir(gopath), p)
+		if filepath.IsAbs(p) {
+			gopath = p
+		} else {
+			gopath = filepath.Join(filepath.Dir(gopath), p)
+		}
 
 		info, err = os.Lstat(gopath)
 		if err != nil {