Import hsqldb18-1.8.0.10 as wip/hsqldb18.

HSQLDB (HyperSQL DataBase) is the leading SQL relational database
engine written in Java. It offers a small, fast multithreaded and
transactional database engine with in-memory and disk-based tables
and supports embedded and server modes.

This package contains library file (hsqldb.jar) only, and it is
old and should be used only for LibreOffice package.
Add hsqldb18
Bump PKGREVISION.

* Remove unused blocks in libreoffice4/Makefile.
* Disable doxygen option explicitly.
* Enable Java option, it is accidentally disabled.