Fix build after merge.
ABI compatibility hack.

Since there is an inline getter for fWebPage, we must not change its
offset in the class. A bool was removed, so insert another field to
compensate...
middle-click open in a new tab even for file: URIs

I don't know what the Qt port was trying to achieve with this code, but
I know it breaks at least this case and it has been annoying me for a
while.
Make the context menu be a pop up menu.

This is better than recreating a menu from another one.