ODT (OpenDocument Text) utils:

* load and store
* plus wrappers for fileset-load and fileset-store that can handle zipped resources in filesets
odt-utils: abstracting out ODT manifest

* utilities to convert from ODT manifest to d:fileset and back
* generate ODT manifest and mimetype when storing ODT
odt-utils: handle formulas in ODT manifest
Add odt:save-as

Exports the ODT file to a (fixed) ODT, a DOC, DOCX, PDF, etc.
Uses jodconverter to connect to a headless instance of LibreOffice/OpenOffice.org.
odt:store: return a <c:result> with the target href
odt-utils: add more convenience steps

* get-file
* update-files
* embed-images
* separate-mathml
Renaming of file-utils, fileset-utils and zip-utils
Better integration with fileset-utils
fixup bc63cb5f53591f
Delete odt:save-as
Merge pull request #18 from daisy-consortium/odt-utils

Close #18