Update UI through async calls MainFrameRepaint and AddressBookRepaint instead of a timer.

- Overall, this is better design
- This fixes problems with the address book UI not updating when the address book is changed through RPC
- Move Statusbar change detection responsibility to ClientModel

src/noui.h

@@ -67,6 +67,10 @@ inline void MainFrameRepaint()
 {
 }
 
+inline void AddressBookRepaint()
+{
+}
+
 inline void InitMessage(const std::string &message)
 {
 }