add method -menucmd:inWindow;
not nil , but obj item
Merge branch 'develop' of https://github.com/dengcqw/XVim-1 into develop

* 'develop' of https://github.com/dengcqw/XVim-1:
  not nil , but obj item
  add method -menucmd:inWindow;
Minor change to :menucmd
  Change the command name  to :xcmenucmd
  Caseinsensitive match for title
  Fix crash when specify a title name for 'Menu holder' (Menu whose action is submenuAction:)
  Update FeatureList.md