allow TempDir to be created in a parent dir

src/main/java/org/cobbzilla/util/io/TempDir.java

@@ -105,16 +105,22 @@ public class TempDir extends File implements Closeable {
 
     public TempDir () { this("700"); }
 
-    public TempDir (String chmod) {
-        super(abs(_tempdir()));
+    public TempDir (File dir) { this(dir, "700"); }
+
+    public TempDir (String chmod) { this(null, chmod); }
+
+    public TempDir (File dir, String chmod) {
+        super(abs(_tempdir(dir)));
         file = new File(super.getPath());
         chmod(file, chmod);
     }
 
-    private static Path _tempdir() {
+    private static Path _tempdir(File dir) {
         try {
             final Set<PosixFilePermission> perms = PosixFilePermissions.fromString("rwx------");
-            return Files.createTempDirectory("tempDir", PosixFilePermissions.asFileAttribute(perms));
+            return dir == null
+                    ? Files.createTempDirectory("tempDir", PosixFilePermissions.asFileAttribute(perms))
+                    : Files.createTempDirectory(dir.toPath(), "tempDir", PosixFilePermissions.asFileAttribute(perms));
         } catch (IOException e) {
             return die("_tempdir: "+shortError(e), e);
         }