finished reimplementation of UserPrefixPin

- implemented 'UserPrefixPin' as default pin if user doesn't provide any
- implemented the option 'AllowUserPrefixPinOverride'
	if 'UseUserPrefixPin' and 'AllowUserPrefixPinOverride' are active and 'UserPrefixPin' the usage if a pin is optional on per-user basis

Signed-off-by: Andrwe Lord Weber <lord-weber-andrwe@andrwe.org>