fix mac specific button modification on addressbookpage
fix mac specific button modification on addressbookpage

- continue the mac behavior of clearing button icons (because it's unusual on mac apps)
- fix: new button variable names, new buttons (verifyMessage, signMessage)

Signed-off-by: Jonas Schnelli <d52d30fd74b5a4c9059a4ca104ac43d29d9077a0@include7.ch>

MidasPaymentLTD/midascoin,MidasPaymentLTD/midascoin,MidasPaymentLTD/midascoin,MidasPaymentLTD/midascoin,MidasPaymentLTD/midascoin