resolve "Undefined attribute name" warning for Angular "ng-" attributes in HTML files

由于这些attributes引起的warning数量较多, 影响直观查找其他warning. 因此选择将这类warning忽视掉:

Project Property -> Validation -> HTML Syntax -> 勾选"Enable project specific settings" -> 勾选"Ignore specified attribute names in validation".

在下面输入框中输入 ng-* , Apply, OK.