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/settingsmanager.cpp

@@ -11,15 +11,15 @@ namespace chatterino {
 
 SettingsManager::SettingsManager()
     : _settings(Path::getAppdataPath() + "settings.ini", QSettings::IniFormat)
-    , theme(_settingsItems, "theme", "dark")
-    , themeHue(_settingsItems, "themeHue", 0)
+    , showTimestamps("/appearance/messages/showTimestamps", true)
+    , showTimestampSeconds("/appearance/messages/showTimestampSeconds", true)
+    , showBadges("/appearance/messages/showBadges", true)
+    , themeName("/appearance/theme/name", "Dark")
+    , themeHue("/appearance/theme/hue", 0.0)
     , selectedUser(_settingsItems, "selectedUser", "")
     , emoteScale(_settingsItems, "emoteScale", 1.0)
     , mouseScrollMultiplier(_settingsItems, "mouseScrollMultiplier", 1.0)
     , scaleEmotesByLineHeight(_settingsItems, "scaleEmotesByLineHeight", false)
-    , showTimestamps("/appearance/messages/showTimestamps", true)
-    , showTimestampSeconds("/appearance/messages/showTimestampSeconds", true)
-    , showBadges("/appearance/messages/showBadges", true)
     , showLastMessageIndicator(_settingsItems, "showLastMessageIndicator", false)
     , allowDouplicateMessages(_settingsItems, "allowDouplicateMessages", true)
     , linksDoubleClickOnly(_settingsItems, "linksDoubleClickOnly", false)