Enable input of addresses in hex

[DEV2DEV-DE]

It would be very handy if register addresses could be directly entered as hex values.
Most documentations show the addresses in hex format and entering would be much easier.

Nice side-effect: The sorting in the object tree will match the values of the addresses.

If the entered address starts with '0x', it's given in hex.
There's no need for the user to calculate.