Fix. add_handle/remove_handle on cURLv3

Add. Examples for cURLv3

examples/cURLv3/file.lua

@@ -0,0 +1,16 @@
+local cURL = require "cURL"
+
+-- open output file
+f = io.open("example_homepage", "w")
+
+cURL.easy{
+  url = "http://www.example.com/",
+  writefunction = f
+}
+:perform()
+:close()
+
+-- close output file
+f:close()
+
+print("Done")

examples/cURLv3/multi.lua

@@ -0,0 +1,17 @@
+local cURL = require("cURL")
+
+-- setup easy and url
+c1 = cURL.easy{url = "http://www.lua.org/"}
+c2 = cURL.easy{url = "http://luajit.org/"}
+
+m = cURL.multi()
+  :add_handle(c1)
+  :add_handle(c2)
+
+local f1 = io.open("lua.html",    "w+b")
+local f2 = io.open("luajit.html", "w+b")
+
+for data, type, easy in m:iperform() do
+    if type == "data" and c1 == easy then f1:write(data) end
+    if type == "data" and c2 == easy then f2:write(data) end
+end

examples/cURLv3/rss.lua

@@ -0,0 +1,47 @@
+-- use LuaExpat and Lua-CuRL together for On-The-Fly XML parsing
+local lxp  = require "lxp"
+local cURL = require "cURL"
+
+-- create XML parser
+items, tags  = {}, {}
+p = lxp.new{
+   StartElement  = function (parser, tagname)
+      tags[#tags + 1] = tagname
+      if (tagname == "item") then
+         items[#items + 1] = {}
+      end
+   end;
+
+   CharacterData = function (parser, str)
+      if (tags[#tags -1] == "item") then
+         --we are parsing a item, get rid of trailing whitespace
+         items[#items][tags[#tags]] = string.gsub(str, "%s*$", "")
+      end
+   end;
+
+   EndElement    = function (parser, tagname)
+      --assuming well formed xml
+      tags[#tags] = nil
+   end;
+}
+
+-- create and setup easy handle
+c = cURL.easy{url = "http://www.lua.org/news.rss"}
+
+-- setup writer function with context
+c:setopt_writefunction(p.parse, p)
+
+-- perform request and close easy handle
+-- perform raise error if parser fail
+c:perform():close()
+
+--finish document
+assert(p:parse())
+p:close()
+
+for i, item in ipairs(items) do 
+   for k, v in pairs(item) do 
+      print(k,v)
+   end
+   print()
+end

src/lua/cURL/impl/cURL.lua

@@ -358,6 +358,9 @@ end
 -------------------------------------------
 local Multi = class(curl.multi) do
 
+local add_handle    = wrap_function("add_handle")
+local remove_handle = wrap_function("remove_handle")
+
 function Multi:__init()
   self._easy = {n = 0}
   return self