adapt SBCOUNTRYCOUNT

Change-Id: Iadf4ae9a569388528f1083c22d6ff197d6479ba9
ditch unused sCurrUNKNOWN and sCurrSYSUNKNOWN strings

Apart from that they weren't currencies and only in the way when adding
a new currency.

Change-Id: If8ca3ab3b37f3617c3f73a01428c0c30dd3481d7
increment SBCOUNTRYCOUNT again, we have 19 currencies 0..18

Apparently this seems to have been forgotten at one occasion.

Change-Id: I1436e412c1308f451d9d953f432a9887cfc99b59