Add listAddressbook to api

listAddressbook returns label and address for each address in the
addressbook.

src/bitmessagemain.py

@@ -164,6 +164,21 @@ class MySimpleXMLRPCRequestHandler(SimpleXMLRPCRequestHandler):
                                        streamNumber, 'enabled': shared.config.getboolean(addressInKeysFile, 'enabled')}, indent=4, separators=(',', ': '))
             data += ']}'
             return data
+        elif method == 'listAddressbook':
+            shared.sqlLock.acquire()
+            shared.sqlSubmitQueue.put('''SELECT label, address from addressbook''')
+            shared.sqlSubmitQueue.put('')
+            queryreturn = shared.sqlReturnQueue.get()
+            shared.sqlLock.release()
+            data = '{"addresses":['
+            for row in queryreturn:
+                label, address = row
+                label = shared.fixPotentiallyInvalidUTF8Data(label)
+                if len(data) > 20:
+                    data += ','
+                data += json.dumps({'label':label.encode('base64'), 'address': address})
+            data += ']}'
+            return data
         elif method == 'createRandomAddress':
             if len(params) == 0:
                 return 'API Error 0000: I need parameters!'