Refactored to use only a default constructor and automatically resize the parameter array each time the size limit is reached.

I used the initial size (WIFI_MANAGER_MAX_PARAMS) as the increment when resizing.
Existing data is coppied to the new array and the old one is free'd.

WiFiManager.h

@@ -64,7 +64,7 @@ class WiFiManagerParameter {
 class WiFiManager
 {
   public:
-    WiFiManager(int max_params=10);
+    WiFiManager();
     ~WiFiManager();
 
     boolean       autoConnect();