Add ParseForm Function & utils test

I guess write would be better

+//Add("/user",&UserController{})
+//Add("/api/list",&RestController{},"*:ListFood")
+//Add("/api/create",&RestController{},"post:CreateFood")
+//Add("/api/update",&RestController{},"put:UpdateFood")
+//Add("/api/delete",&RestController{},"delete:DeleteFood")
+//Add("/api",&RestController{},"get,post:ApiFunc")
+//Add("/simple",&SimpleController{},"get:GetFunc;post:PostFunc")

Valid

Valid

Fixed bug: error page cannot show correct corresponding status code

Sync documentation of English with Chinese version.