DeviceProductName cleaning

_For the context, I'm in the process of trying to reset Opener stack and reinitializing it during userapp runtime._

1. I checked for memory leaks and valgrind shows me this report:

```
==67425== 4 bytes in 1 blocks are still reachable in loss record 1 of 201
==67425== at 0x484AC34: calloc (vg_replace_malloc.c:1595)
==67425== by 0x2757F0: SetCipShortStringByData (cipstring.c:242)
==67425== by 0x2757F0: SetCipShortStringByCstr (cipstring.c:263)
==67425== by 0x271C02: SetDeviceProductName (cipidentity.c:99)
==67425== by 0x271C02: SetDeviceProductName (cipidentity.c:95)
==67425== by 0x271C02: CipIdentityInit (cipidentity.c:267)
==67425== by 0x26BCC0: CipStackInit (cipcommon.c:49)
```

It seems ShutdownCipStack() does not free g_identity.product_name?

2. Do you see any other Opener global variables that should be reset that is not handled by the stack itself?

I'm wondering if I need to call DoublyLinkedListDestroy on connection_list for instance.

Thanks by advance for any input
Vincent