Add skynet.coroutine module

test/testcoroutine.lua

@@ -0,0 +1,24 @@
+local skynet = require "skynet"
+-- You should use skynet.coroutine instead of origin coroutine in skynet
+local coroutine = require "skynet.coroutine"
+
+local function test(n)
+	print ("begin", coroutine.isskynetcoroutine())
+	for i=1,n do
+		skynet.sleep(100)
+		coroutine.yield(i)
+	end
+	print "end"
+	return false
+end
+
+skynet.start(function()
+	print("Is the main thead a skynet coroutine ?", coroutine.isskynetcoroutine(coroutine.running()))	-- always false
+	print(coroutine.resume(coroutine.running()))	-- always return false
+	local f = coroutine.wrap(test)
+	repeat
+		local n = f(5)
+		print(n)
+	until not n
+	skynet.exit()
+end)