Adds the ability to cache page previews.
Features
- Improved performance when processing Slides documents.
- Added the ability to cache page previews.
- Added the ability to annotate documents of older formats for Slides, Words and Cells documents (.ppt, .doc, .xls).
- Added the ability to add a text caption for distance annotation for Cells, Diagrams and Slides documents.
- Refactored logic for getting pages for Slides documents.
