feat: implement mcrfpy.Timer object with pause/resume/cancel capabilities closes #103

- Created PyTimer.h/cpp with object-oriented timer interface
- Enhanced PyTimerCallable with pause/resume state tracking
- Added timer control methods: pause(), resume(), cancel(), restart()
- Added timer properties: interval, remaining, paused, active, callback
- Fixed timing logic to prevent rapid catch-up after resume
- Timer objects automatically register with game engine
- Added comprehensive test demonstrating all functionality

src/PyCallable.h

@@ -10,7 +10,7 @@ protected:
     ~PyCallable();
     PyObject* call(PyObject*, PyObject*);
 public:
-    bool isNone();
+    bool isNone() const;
 };
 
 class PyTimerCallable: public PyCallable
@@ -19,11 +19,32 @@ private:
     int interval;
     int last_ran;
     void call(int);
+    
+    // Pause/resume support
+    bool paused;
+    int pause_start_time;
+    int total_paused_time;
+    
 public:
     bool hasElapsed(int);
     bool test(int);
     PyTimerCallable(PyObject*, int, int);
     PyTimerCallable();
+    
+    // Timer control methods
+    void pause(int current_time);
+    void resume(int current_time);
+    void restart(int current_time);
+    void cancel();
+    
+    // Timer state queries
+    bool isPaused() const { return paused; }
+    bool isActive() const { return !isNone() && !paused; }
+    int getInterval() const { return interval; }
+    void setInterval(int new_interval) { interval = new_interval; }
+    int getRemaining(int current_time) const;
+    PyObject* getCallback() { return target; }
+    void setCallback(PyObject* new_callback);
 };
 
 class PyClickCallable: public PyCallable