Bug#1042697: (no subject)

[Kentaro HAYASHI]

NOTE for sphinx 7 when it is landed into sid:

* doc/files.am should be patched to eliminate jquery.js and
  underscore.js dependency or use  python3-sphinxcontrib.jquery and so
  on.
* debian/control
  * add missing libjs-sphixdoc dependency.
* debian/groonga-doc.links should be updated.
  * drop jquery and underscore 
  * add other searchtools language_data sphihx_highlight doctools