Updates the EPUB plug-in and dependency plugins to fix issues reported in EPUB issue #90.
Corrects the following issues:
- Corrected use of unset $topics.output.dir in navigation URLs
- Properly declare use of MathML in the EPUB manifest
- Corrected bug in generation of height and width values for images (was resulting in "NaN")
- Correctly preserve SVG namespace on SVG images included in the EPUB content
Test with OT 3.6.1
This release includes updates to all the plug-in packages because of changes ot common plugins but the focus was on the EPUB plug-in