Beginning of libtextsecure refactor.

1) Break out appropriate components.

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

library/src/org/whispersystems/textsecure/push/PushAttachmentData.java

@@ -1,21 +1,34 @@
 package org.whispersystems.textsecure.push;
 
+import java.io.InputStream;
+
 public class PushAttachmentData {
 
-  private final String contentType;
-  private final byte[] data;
+  private final String      contentType;
+  private final InputStream data;
+  private final long        dataSize;
+  private final byte[]      key;
 
-  public PushAttachmentData(String contentType, byte[] data) {
+  public PushAttachmentData(String contentType, InputStream data, long dataSize, byte[] key) {
     this.contentType = contentType;
     this.data        = data;
+    this.dataSize    = dataSize;
+    this.key         = key;
   }
 
   public String getContentType() {
     return contentType;
   }
 
-  public byte[] getData() {
+  public InputStream getData() {
     return data;
   }
 
+  public long getDataSize() {
+    return dataSize;
+  }
+
+  public byte[] getKey() {
+    return key;
+  }
 }