Make it work with EiffelStudio 7.2

The EWF version in EiffelStudio 7.2 has quite changed and is incompatible
with the EWF version that shipped with EiffelStudio 7.1.
This commit make it work with EiffelStudio 7.2.
A version that works with EiffelStudio 7.1 is still available
in the ise7.1 tag