Start work on protocol capabilities (#337)

classes.py

@@ -1377,6 +1377,9 @@ class Protocol():
         self.conf_keys = {'ip', 'port', 'hostname', 'sid', 'sidrange', 'protocol', 'sendpass',
                           'recvpass'}
 
+        # Defines a set of PyLink protocol capabilities
+        self.protocol_caps = set()
+
     def validateServerConf(self):
         """Validates that the server block given contains the required keys."""
         for k in self.conf_keys:

protocols/ircs2s_common.py

@@ -9,6 +9,11 @@ from pylinkirc.log import log
 
 class IRCS2SProtocol(Protocol):
 
+    def __init__(self, irc):
+        super().__init__(irc)
+        self.protocol_caps = {'can-spawn-clients', 'has-ts', 'can-host-relay',
+                              'can-track-servers'}
+
     def checkCollision(self, nick):
         """
         Nick collision checker.