Resolve most compiler warnings (#1053)

dGame/dComponents/RebuildComponent.cpp

@@ -234,6 +234,7 @@ void RebuildComponent::Update(float deltaTime) {
 		}
 		break;
 	}
+	case REBUILD_RESETTING: break;
 	}
 }
 

dGame/dGameMessages/GameMessages.cpp

@@ -2570,7 +2570,7 @@ void GameMessages::HandleBBBSaveRequest(RakNet::BitStream* inStream, Entity* ent
 
 	//We runs this in async because the http library here is blocking, meaning it'll halt the thread.
 	//But we don't want the server to go unresponsive, because then the client would disconnect.
-	std::async(std::launch::async, [&]() {
+	auto returnVal = std::async(std::launch::async, [&]() {
 
 		//We need to get a new ID for our model first:
 		ObjectIDManager::Instance()->RequestPersistentID([=](uint32_t newID) {

dGame/dUtilities/Mail.cpp

@@ -130,7 +130,7 @@ void Mail::HandleMailStuff(RakNet::BitStream* packet, const SystemAddress& sysAd
 	int mailStuffID = 0;
 	packet->Read(mailStuffID);
 
-	std::async(std::launch::async, [packet, &sysAddr, entity, mailStuffID]() {
+	auto returnVal = std::async(std::launch::async, [packet, &sysAddr, entity, mailStuffID]() {
 		Mail::MailMessageID stuffID = MailMessageID(mailStuffID);
 		switch (stuffID) {
 		case MailMessageID::AttachmentCollect:
@@ -393,7 +393,7 @@ void Mail::HandleMailRead(RakNet::BitStream* packet, const SystemAddress& sysAdd
 }
 
 void Mail::HandleNotificationRequest(const SystemAddress& sysAddr, uint32_t objectID) {
-	std::async(std::launch::async, [&]() {
+	auto returnVal = std::async(std::launch::async, [&]() {
 		sql::PreparedStatement* stmt = Database::CreatePreppedStmt("SELECT id FROM mail WHERE receiver_id=? AND was_read=0");
 		stmt->setUInt(1, objectID);
 		sql::ResultSet* res = stmt->executeQuery();