Fix Bullet Behavior on export

[mark-dce]

• 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

[mark-dce]

Replaced by https://github.com/curationexperts/tufts-image-library/pull/211