migrate conversation list to RecyclerView

fixes #2488
fixes #2333
// FREEBIE

src/org/thoughtcrime/securesms/ConversationActivity.java

@@ -1368,11 +1368,6 @@ public class ConversationActivity extends PassphraseRequiredActionBarActivity
     public void onFocusChange(View v, boolean hasFocus) {}
   }
 
-  @Override
-  public void setComposeText(String text) {
-    this.composeText.setText(text);
-  }
-
   @Override
   public void setThreadId(long threadId) {
     this.threadId = threadId;