When building Go and Sign out URLs, make them absolute
When building Go and Sign out URLs, make them absolute

This is a regression caused by removal of the <base> tag.

mathjazz/pontoon,jotes/pontoon,m8ttyB/pontoon,mathjazz/pontoon,yfdyh000/pontoon,sudheesh001/pontoon,sudheesh001/pontoon,jotes/pontoon,jotes/pontoon,mastizada/pontoon,mathjazz/pontoon,mozilla/pontoon,mastizada/pontoon,m8ttyB/pontoon,mozilla/pontoon,mozilla/pontoon,vivekanand1101/pontoon,participedia/pontoon,mastizada/pontoon,mozilla/pontoon,participedia/pontoon,sudheesh001/pontoon,mathjazz/pontoon,mozilla/pontoon,m8ttyB/pontoon,vivekanand1101/pontoon,vivekanand1101/pontoon,m8ttyB/pontoon,participedia/pontoon,yfdyh000/pontoon,participedia/pontoon,yfdyh000/pontoon,jotes/pontoon,mathjazz/pontoon,vivekanand1101/pontoon,sudheesh001/pontoon,yfdyh000/pontoon,mastizada/pontoon