Update for OT 3.6+

[drmacro]

Update EPUB transform to work properly with OT 3.6+

[drmacro]

Several changes required to react to changes to the OT in version 3:

• Must use pipeline elements to run XSLTs in order to have access to new storage API files (i.e., job.xml)
• Graphic references are rewritten in the temp files and must be dereferenced via the job.xml file

[drmacro]

Turns out using is both not required and breaks a number of things in the current transform, so not doing that.
Likewise, graphic references are not rewritten like they are in the PDF transform, so not an issue.

However, a number of other small issues have been fixed, including restoring copying of images properly and other small details that let to epubcheck errors and warnings.

WIth the various changes under this issue, the D4P user guide EPUB passes the latest epubcheck without any warnings or errors. Likewise, kindlepreviewer generates a good Kindle book without any issues from the D4P user guide EPUB.