implement initial event manager

c_os/user/KeyEventManager.cc

@@ -0,0 +1,14 @@
+#include "user/KeyEventManager.h"
+#include "kernel/Globals.h"
+
+void KeyEventManager::subscribe(KeyEventListener& listener) {
+    this->listeners[this->num_subscribed] = &listener;
+    this->num_subscribed = this->num_subscribed + 1;
+}
+
+void KeyEventManager::broadcast(char c) {
+    for (unsigned int i = 0; i < this->num_subscribed; ++i) {
+        this->listeners[i]->trigger(c);  // Sets lastChar
+        scheduler.deblock(&this->listeners[i]->thread);
+    }
+}