wicketforge

How do I make IntelliJ recognize wicket html tags?

I'm using IntellIJ with Apache Wicket and IntelliJ is showing me that tags like <wicket:extend> and <wicket:container> and adding wicket:id to other html tags is not valid. What steps do I need to take to make IntelliJ recognize the wicket tags? I'm using IntelliJ Ultimate 9 with the wicketforge plugin. ...