message: Update WiFiManager.cpp
  adds more heap debug debug_level DEBUG_MAX to enable
  #518
diff: @@ -2453,8 +2453,15 @@ void WiFiManager::DEBUG_WM(wm_debuglevel_t level,Generic text,Genericb textb) {
  if(!_debug || _debugLevel < level) return;
  if(_debugLevel >= DEBUG_MAX){
  - _debugPort.print("MEM: ");
  - _debugPort.println((String)ESP.getFreeHeap());
  + _debugPort.println("MEM: ");
  + uint32_t free;
  + uint16_t max;
  + uint8_t frag;
  + ESP.getHeapStats(&free, &max, &frag);
  + _debugPort.printf("[MEM] free: %5d | max: %5d | frag: %3d%% \n", free, max, frag);
  + // _debugPort.print((String)ESP.getFreeHeap());
  + // _debugPort.print((String)ESP.getMaxFreeBlockSize());
  + // _debugPort.print((String)ESP.getHeapFragmentation());
  }
  _debugPort.print("*WM: ");
  if(_debugLevel == DEBUG_DEV) _debugPort.print("["+(String)level+"] ");
  