wechat registration

[ma3310]

• [x] apply table with edit page
• [x] migrate menu fetch function
• [x] migrate menu create / delete function
• [x] migrate welcome and contact us function
• [ ] wechat login from mobile and PC
  • [ ] forward user to wechat login with fallback
  • [ ] receive back info to create user
• [ ] wechat entity
  • [ ] QR code support
• [x] wechat server echo - for subscription and service accounts