Fixed VFS file field error with preselected files which are not in a
site.
HSQLDB upgrade to 2.2.8
Set extended persistence context explicitly
JPA: Initialize m_factoryTable outside init() method.

This allows methods getFactory(String) and createEntityManager(String)
methods to be useful even in case OpenCms installation doesn't use JPA
layer. For example OpenCms can use MySql driver with module which uses
JPA.
Fixing issues with HSQLDB driver update.