Beginning of libtextsecure refactor.

1) Break out appropriate components.

2) Switch the incoming pipeline from SendReceiveService to
   the JobManager.

src/org/thoughtcrime/securesms/jobs/requirements/MasterSecretRequirement.java

@@ -0,0 +1,26 @@
+package org.thoughtcrime.securesms.jobs.requirements;
+
+import android.content.Context;
+
+import org.thoughtcrime.securesms.service.KeyCachingService;
+import org.whispersystems.jobqueue.dependencies.ContextDependent;
+import org.whispersystems.jobqueue.requirements.Requirement;
+
+public class MasterSecretRequirement implements Requirement, ContextDependent {
+
+  private transient Context context;
+
+  public MasterSecretRequirement(Context context) {
+    this.context = context;
+  }
+
+  @Override
+  public boolean isPresent() {
+    return KeyCachingService.getMasterSecret(context) != null;
+  }
+
+  @Override
+  public void setContext(Context context) {
+    this.context = context;
+  }
+}

src/org/thoughtcrime/securesms/jobs/requirements/MasterSecretRequirementProvider.java

@@ -0,0 +1,36 @@
+package org.thoughtcrime.securesms.jobs.requirements;
+
+import android.content.BroadcastReceiver;
+import android.content.Context;
+import android.content.Intent;
+import android.content.IntentFilter;
+
+import org.thoughtcrime.securesms.service.KeyCachingService;
+import org.whispersystems.jobqueue.requirements.RequirementListener;
+import org.whispersystems.jobqueue.requirements.RequirementProvider;
+
+public class MasterSecretRequirementProvider implements RequirementProvider {
+
+  private final BroadcastReceiver newKeyReceiver;
+
+  private RequirementListener listener;
+
+  public MasterSecretRequirementProvider(Context context) {
+    this.newKeyReceiver = new BroadcastReceiver() {
+      @Override
+      public void onReceive(Context context, Intent intent) {
+        if (listener != null) {
+          listener.onRequirementStatusChanged();
+        }
+      }
+    };
+
+    IntentFilter filter = new IntentFilter(KeyCachingService.NEW_KEY_EVENT);
+    context.registerReceiver(newKeyReceiver, filter, KeyCachingService.KEY_PERMISSION, null);
+  }
+
+  @Override
+  public void setListener(RequirementListener listener) {
+    this.listener = listener;
+  }
+}