Support implicitly syncing on login

Whether to sync after connecting or not is desired depends on the application,
and it's better to remove the possibility of doing so. Having to done one
explicit call to :sync() is not a big deal, and makes the intention of code
using the module clearer. And our code simpler.

matrix/client.lua

@@ -323,43 +323,35 @@ Client.__name  = "matrix.client"
 Client.__index = Client
 
 setmetatable(Client, { __call = function (self, base_url, token, http_client)
-   local c = eventable.object(setmetatable({
+   return eventable.object(setmetatable({
       presence = {},  -- Indexed by user_id
       rooms = {},     -- Indexed by room_id
       _log = get_debug_log_function(),
       _api = API(base_url, token, http_client),
    }, Client))
-   -- Do an initial sync if a token was provided on construction.
-   if token then
-      c:_sync()
-   end
-   return c
 end })
 
 function Client:__tostring()
    return self.__name .. "{" .. self._api.base_url .. "}"
 end
 
-function Client:register_with_password(username, password, no_sync)
+function Client:register_with_password(username, password)
    return self:_logged_in(self._api:register("m.login.password",
-      { user = username, password = password }), no_sync)
+      { user = username, password = password }))
 end
 
-function Client:login_with_password(username, password, no_sync)
+function Client:login_with_password(username, password)
    return self:_logged_in(self._api:login("m.login.password",
-      { user = username, password = password }), no_sync)
+      { user = username, password = password }))
 end
 
-function Client:_logged_in(response, no_sync)
+function Client:_logged_in(response)
    self._log("logged-in: %s", response.user_id)
    self.user_id    = response.user_id
    self.homeserver = response.home_server
    self.token      = response.access_token
    self._api.token = response.access_token
    self:fire("logged-in")
-   if not no_sync then
-      self:_sync()
-   end
    return self.token
 end