NetEq now works with packets as values, rather than pointers.

PacketList is now list<Packet> instead of list<Packet*>.
Splicing the lists in NetEqImpl::InsertPacketInternal instead of
moving packets. Avoid moving the packet when doing Rfc3389Cng.
Removed PacketBuffer::DeleteFirstPacket and DeleteAllPackets.

BUG=chromium:657300

Review-Url: https://codereview.webrtc.org/2425223002
Cr-Commit-Position: refs/heads/master@{#14747}

webrtc/modules/audio_coding/neteq/timestamp_scaler.cc

@@ -29,7 +29,7 @@ void TimestampScaler::ToInternal(Packet* packet) {
 void TimestampScaler::ToInternal(PacketList* packet_list) {
   PacketList::iterator it;
   for (it = packet_list->begin(); it != packet_list->end(); ++it) {
-    ToInternal(*it);
+    ToInternal(&(*it));
   }
 }