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>

reddink/reddcoin,joroob/reddcoin,reddcoin-project/reddcoin,bmp02050/ReddcoinUpdates,reddcoin-project/reddcoin,coinkeeper/2015-06-22_19-10_cannacoin,reddink/reddcoin,Cannacoin-Project/Cannacoin,reddcoin-project/reddcoin,Cannacoin-Project/Cannacoin,coinkeeper/2015-06-22_18-46_reddcoin,Cannacoin-Project/Cannacoin,joroob/reddcoin,coinkeeper/2015-06-22_19-10_cannacoin,coinkeeper/2015-06-22_18-46_reddcoin,Cannacoin-Project/Cannacoin,reddcoin-project/reddcoin,coinkeeper/2015-06-22_19-10_cannacoin,joroob/reddcoin,bmp02050/ReddcoinUpdates,reddcoin-project/reddcoin,Cannacoin-Project/Cannacoin,joroob/reddcoin,coinkeeper/2015-06-22_18-46_reddcoin,reddink/reddcoin,ahmedbodi/poscoin,coinkeeper/2015-06-22_18-46_reddcoin,ahmedbodi/poscoin,coinkeeper/2015-06-22_18-46_reddcoin,coinkeeper/2015-06-22_19-10_cannacoin,bmp02050/ReddcoinUpdates,ahmedbodi/poscoin,reddink/reddcoin,reddcoin-project/reddcoin,ahmedbodi/poscoin,bmp02050/ReddcoinUpdates,bmp02050/ReddcoinUpdates,reddink/reddcoin,coinkeeper/2015-06-22_19-10_cannacoin,joroob/reddcoin,ahmedbodi/poscoin