move some module into skynet/

test/testdns.lua

@@ -1,5 +1,5 @@
 local skynet = require "skynet"
-local dns = require "dns"
+local dns = require "skynet.dns"
 
 skynet.start(function()
 	print("nameserver:", dns.server())	-- set nameserver

test/testhttp.lua

@@ -1,6 +1,6 @@
 local skynet = require "skynet"
 local httpc = require "http.httpc"
-local dns = require "dns"
+local dns = require "skynet.dns"
 
 local function main()
 	httpc.dns()	-- set dns server

test/testmemlimit.lua

@@ -1,6 +1,15 @@
 local skynet = require "skynet"
 
-local names = {"cluster", "dns", "mongo", "mysql", "redis", "sharedata", "socket", "sproto"}
+local names = {
+	"cluster",
+	"skynet.db.dns",
+	"skynet.db.mongo",
+	"skynet.db.mysql",
+	"skynet.db.redis",
+	"sharedata",
+	"skynet.socket",
+	"sproto"
+}
 
 -- set sandbox memory limit to 1M, must set here (at start, out of skynet.start)
 skynet.memlimit(1 * 1024 * 1024)

test/testmongodb.lua

@@ -1,5 +1,5 @@
 local skynet = require "skynet"
-local mongo = require "mongo"
+local mongo = require "skynet.db.mongo"
 local bson = require "bson"
 
 local host, db_name = ...

test/testmysql.lua

@@ -1,5 +1,5 @@
 local skynet = require "skynet"
-local mysql = require "mysql"
+local mysql = require "skynet.db.mysql"
 
 local function dump(obj)
     local getIndent, quoteStr, wrapKey, wrapVal, dumpObj

test/testpipeline.lua

@@ -1,5 +1,5 @@
 local skynet = require "skynet"
-local redis = require "redis"
+local redis = require "skynet.db.redis"
 
 local conf = {
 	host = "127.0.0.1",

test/testredis.lua

@@ -1,5 +1,5 @@
 local skynet = require "skynet"
-local redis = require "redis"
+local redis = require "skynet.db.redis"
 
 local conf = {
 	host = "127.0.0.1" ,

test/testredis2.lua

@@ -1,5 +1,5 @@
 local skynet = require "skynet"
-local redis  = require "redis"
+local redis  = require "skynet.db.redis"
 
 local db
 

test/testsocket.lua

@@ -1,5 +1,5 @@
 local skynet = require "skynet"
-local socket = require "socket"
+local socket = require "skynet.socket"
 
 local mode , id = ...
 

test/testudp.lua

@@ -1,5 +1,5 @@
 local skynet = require "skynet"
-local socket = require "socket"
+local socket = require "skynet.socket"
 
 local function server()
 	local host