Make the switch to gradle!

1) ABS is now published as an AAR, so we can eliminate all local
   dependencies and bundled jars.

2) Upgrade to ABS 4.4.0 (The Last Release) and deal with the loss
   of Sherlock.Dialog by faking it with our own themes.

3) Remove all traces of ant. The modern world is here.

src/org/thoughtcrime/securesms/AutoInitiateActivity.java

@@ -16,6 +16,7 @@
  */
 package org.thoughtcrime.securesms;
 
+import android.app.Activity;
 import android.content.Context;
 import android.content.SharedPreferences;
 import android.os.Bundle;
@@ -40,7 +41,7 @@ import org.thoughtcrime.securesms.util.MemoryCleaner;
  * @author Moxie Marlinspike
  *
  */
-public class AutoInitiateActivity extends PassphraseRequiredSherlockActivity {
+public class AutoInitiateActivity extends Activity {
 
   private long threadId;
   private Recipient recipient;