Experimental emoji sets implemented

Fixes #376

src/widgets/emotepopup.cpp

@@ -144,8 +144,8 @@ void EmotePopup::loadEmojis()
     builder.getMessage()->flags |= Message::DisableCompactEmotes;
 
     emojis.each([&builder](const QString &key, const auto &value) {
-        builder.append((new EmoteElement(value.emoteData, MessageElement::Flags::AlwaysShow))
-                           ->setLink(Link(Link::Type::InsertText, ":" + value.shortCode + ":")));
+        builder.append((new EmoteElement(value->emoteData, MessageElement::Flags::AlwaysShow))
+                           ->setLink(Link(Link::Type::InsertText, ":" + value->shortCode + ":")));
     });
     emojiChannel->addMessage(builder.getMessage());
 

src/widgets/settingspages/aboutpage.cpp

@@ -82,6 +82,21 @@ AboutPage::AboutPage()
             addLicense(*form, "Websocketpp", "https://www.zaphoyd.com/websocketpp/",
                        ":/licenses/websocketpp.txt");
         }
+
+        auto attributions = layout.emplace<QGroupBox>("Attributions...");
+        {
+            auto l = attributions.emplace<QVBoxLayout>();
+
+            // clang-format off
+            l.emplace<QLabel>("EmojiOne 2 and 3 emojis provided by <a href=\"https://www.emojione.com/\">EmojiOne</a>");
+            l.emplace<QLabel>("Twemoji emojis provided by <a href=\"https://github.com/twitter/twemoji\">Twitter's Twemoji</a>");
+            l.emplace<QLabel>("Facebook emojis provided by <a href=\"https://facebook.com\">Facebook</a>");
+            l.emplace<QLabel>("Apple emojis provided by <a href=\"https://apple.com\">Apple</a>");
+            l.emplace<QLabel>("Google emojis provided by <a href=\"https://google.com\">Google</a>");
+            l.emplace<QLabel>("Messenger emojis provided by <a href=\"https://facebook.com\">Facebook</a>");
+            l.emplace<QLabel>("Emoji datasource provided by <a href=\"https://www.iamcal.com/\">Cal Henderson</a>");
+            // clang-format on
+        }
     }
 
     layout->addStretch(1);

src/widgets/settingspages/appearancepage.cpp

@@ -142,10 +142,24 @@ AppearancePage::AppearancePage()
 
             scaleLabel->setText(QString::number(app->settings->emoteScale.getValue()));
         }
+
+        {
+            auto *combo = new QComboBox(this);
+            combo->addItems({"EmojiOne 2", "EmojiOne 3", "Twitter", "Facebook", "Apple", "Google",
+                             "Messenger"});
+
+            QObject::connect(combo, &QComboBox::currentTextChanged, [](const QString &str) {
+                getApp()->settings->emojiSet = str;  //
+            });
+
+            auto hbox = emotes.emplace<QHBoxLayout>().withoutMargin();
+            hbox.emplace<QLabel>("Emoji set");
+            hbox.append(combo);
+        }
     }
 
     layout->addStretch(1);
-}  // namespace settingspages
+}
 
 QLayout *AppearancePage::createThemeColorChanger()
 {