A lot of changes

Remove unused constructor of messages::Message
Fixed LimitedQueueSnapshot _-prefixes
Changed LimitedQueueSnapshot's usage of int to std::size_t
ColorScheme is no longer a singleton
Created a "BaseWidget" class which is pretty much a QWidget except it
has a reference of ColorScheme since most widgets will need a reference
to the style they should use.
BaseWidget can be implemented either with a BaseWidget parent (which
will copy the ColorScheme reference from the parent) or with a
normal QWidget parent and an explicit ColorScheme reference.
Save main window geometry on close
Fix font changing in the Settings Dialog
Update settings library version

src/widgets/chatwidget.cpp

@@ -30,8 +30,8 @@ inline void ezShortcut(ChatWidget *w, const char *key, T t)
 
 }  // namespace
 
-ChatWidget::ChatWidget(ChannelManager &_channelManager, QWidget *parent)
-    : QWidget(parent)
+ChatWidget::ChatWidget(ChannelManager &_channelManager, NotebookPage *parent)
+    : BaseWidget(parent)
     , channelManager(_channelManager)
     , channel(_channelManager.getEmpty())
     , vbox(this)
@@ -142,7 +142,7 @@ void ChatWidget::setChannel(std::shared_ptr<Channel> _newChannel)
 
     auto snapshot = this->channel->getMessageSnapshot();
 
-    for (int i = 0; i < snapshot.getSize(); i++) {
+    for (int i = 0; i < snapshot.getLength(); i++) {
         SharedMessageRef deleted;
 
         auto messageRef = new MessageRef(snapshot[i]);
@@ -199,7 +199,7 @@ void ChatWidget::paintEvent(QPaintEvent *)
     // color the background of the chat
     QPainter painter(this);
 
-    painter.fillRect(this->rect(), ColorScheme::getInstance().ChatBackground);
+    painter.fillRect(this->rect(), this->colorScheme.ChatBackground);
 }
 
 void ChatWidget::load(const boost::property_tree::ptree &tree)
@@ -241,7 +241,8 @@ void ChatWidget::doChangeChannel()
 void ChatWidget::doPopup()
 {
     // TODO: Copy signals and stuff too
-    auto widget = new ChatWidget(this->channelManager);
+    auto widget =
+        new ChatWidget(this->channelManager, static_cast<NotebookPage *>(this->parentWidget()));
     widget->setChannelName(this->getChannelName());
     widget->show();
 }