Perform initial refactoring work

Things that were once singletons are no longer singletons, but are
instead stored in the "Application" singleton

Some singletons still remain, and some renaming/renamespacing is left

src/singletons/emotemanager.hpp

@@ -23,9 +23,12 @@ namespace singletons {
 class EmoteManager
 {
     EmoteManager();
+    friend class Application;
 
 public:
-    static EmoteManager &getInstance();
+    ~EmoteManager() = delete;
+
+    void initialize();
 
     void loadGlobalEmotes();