Reworked the project organization.
DocGenerator class is removed and most of its contents moved to the Template class.
Some exceptions removed in favor of using existing java exceptions.
JODConverter used to convert template instances to PDF from soffice service instead of running a subprocess every time.
Template instances and pdf files no longer necessarily stored in disk, they can be in streams, accelerating the process.
Document load and save exceptions added to encapsulate the very general exception that is thrown by these processes.
Test files corrected to acommodate these changes.
Added script to run libreoffice as a service.