wireproto: add decorator for wire protocol command

Move move in the same direction we took for command line commands. each wire
protocol function will be decorated with its name and arguments.

Beside beside easier to read, this open the road to easily adding more metadata
(like security level or return type)

mercurial/wireproto.py

@@ -471,6 +471,16 b' def options(cmd, keys, others):'
                          % (cmd, ",".join(others)))
     return opts
 
+# list of commands
+commands = {}
+
+def wireprotocommand(name, args=''):
+    """decorator for wireprotocol command"""
+    def register(func):
+        commands[name] = (func, args)
+        return func
+    return register
+
 def batch(repo, proto, cmds, others):
     repo = repo.filtered("served")
     res = []
@@ -770,7 +780,7 b' def unbundle(repo, proto, heads):'
         fp.close()
         os.unlink(tempname)
 
-commands = {
+commands.update({
     'batch': (batch, 'cmds *'),
     'between': (between, 'pairs'),
     'branchmap': (branchmap, ''),
@@ -788,4 +798,4 b' commands = {'
     'pushkey': (pushkey, 'namespace key old new'),
     'stream_out': (stream, ''),
     'unbundle': (unbundle, 'heads'),
-}
+})