Add device name variable for scripting

[chriscn]

It would be nice to be able to access the device name using the special variables section. I understand there is frnm for the Friendly Name. However perhaps dvnm for device name.

[gemu2015]

ok, is implemented
it will be included in next pr

[chriscn]

Awesome thank you. I did have a look at the code but not very skilled with C.