Fix Bullet Behavior on export

* Use JSON for data transfer between ruby and java
* Explicitly generate metadata lines rather than using carriage returns for bulleting
* Support arbitrary numbers of creator, date, and description elements on each slide
* Resize text to fix on slide as necessary
* Modularize metadata formatting to simplify future changes
* Misc changes attempting to make MS-Office, LibreOffice, OpenOffice, and PDF output more consistent