Added support for consumer kwargs

I have an app that uses consumer, but needs to pass in some kwargs
for consumption at consumer function call time.  This patch adds
kwargs support to consumer creation as well as passing those kwargs
at consumer callback time.

aprslib/inet.py

@@ -157,7 +157,7 @@ def sendall(self, line):
             self.close()
             raise ConnectionError(str(exp))
 
-    def consumer(self, callback, blocking=True, immortal=False, raw=False):
+    def consumer(self, callback, blocking=True, immortal=False, raw=False, **kwargs):
         """
         When a position sentence is received, it will be passed to the callback function
 
@@ -180,9 +180,9 @@ def consumer(self, callback, blocking=True, immortal=False, raw=False):
                 for line in self._socket_readlines(blocking):
                     if line[0:1] != b'#':
                         if raw:
-                            callback(line)
+                            callback(line, **kwargs)
                         else:
-                            callback(self._parse(line))
+                            callback(self._parse(line), **kwargs)
                     else:
                         self.logger.debug("Server: %s", line.decode('utf8'))
             except ParseError as exp: