[Firebird-docs] Documentation build now replaced

[Mark R. <ma...@la...>]

I have just merged the changes to the documentation project. The build 
has now switched to gradle, and the old ant build is no longer available.

I have also updated the Firebird Docbuilding Howto on uploaded it to the 
site.

If you run into any problems, let me know.

Mark
-- 
Mark Rotteveel