support "$$" as a literal "$" in alias arg replacements

modules/aliases.py

@@ -7,6 +7,8 @@ SETTING_PREFIX = "command-alias-"
 
 class Module(ModuleManager.BaseModule):
     def _arg_replace(self, s, args_split):
+        parts = s.split("$$")
+        for i, part in enumerate(parts):
             for match in REGEX_ARG_NUMBER.finditer(s):
                 if match.group(1):
                     index = int(match.group(1))
@@ -21,8 +23,8 @@ class Module(ModuleManager.BaseModule):
                     replace = " ".join(args_split[index:])
                 else:
                     replace = args_split[index]
-            s = s.replace(match.group(0), replace)
-        return s
+                parts[i] = part.replace(match.group(0), replace)
+        return "$".join(parts)
 
     def _get_alias(self, server, target, command):
         setting = "%s%s" % (SETTING_PREFIX, command)