Reformat Search page headings

OME-DCO-1.1-Signed-off-by: Sebastien Besson <seb.besson@gmail.com> (github: sbesson)
Restructure omero.api.Search table using list-table

OME-DCO-1.1-Signed-off-by: Sebastien Besson <seb.besson@gmail.com> (github: sbesson)
Unify markup in Search with the rest of the documentation

- Wrap lines after 78 charachters
- Use file and envvar markups when possible
- Use $ as the leading character for UNIX command lines

OME-DCO-1.1-Signed-off-by: Sebastien Besson <seb.besson@gmail.com> (github: sbesson)
Add percent indexed SQL command to the Re-indexing section

OME-DCO-1.1-Signed-off-by: Sebastien Besson <seb.besson@gmail.com> (github: sbesson)
Move search indexing/re-indexing to the sysadmin section

OME-DCO-1.1-Signed-off-by: Sebastien Besson <seb.besson@gmail.com> (github: sbesson)
Improve re-indexing title style and add sub-titles

OME-DCO-1.1-Signed-off-by: Sebastien Besson <seb.besson@gmail.com> (github: sbesson)
Add table for re-indexing time of production servers

OME-DCO-1.1-Signed-off-by: Sebastien Besson <seb.besson@gmail.com> (github: sbesson)
re-indexation -> re-indexing

OME-DCO-1.1-Signed-off-by: Sebastien Besson <seb.besson@gmail.com> (github: sbesson)
Define all omero.search.xxx properties in the Search sysadmin page

This commit should group all sysadmin content related to search into a single
page. Additionally, the omero.search.xx properties are defined as glossady
(i.e. indexed) and referred to using the `term` markup in the rest of the
documentation.

OME-DCO-1.1-Signed-off-by: Sebastien Besson <seb.besson@gmail.com> (github: sbesson)
Improve title of sysadmin search section

OME-DCO-1.1-Signed-off-by: Sebastien Besson <seb.besson@gmail.com> (github: sbesson)
Move paragraph back to developer doc and add cross-references

OME-DCO-1.1-Signed-off-by: Sebastien Besson <seb.besson@gmail.com> (github: sbesson)
Use PersistentEventLogLoader.v2.current_id as the defaut

- Move the discussion on configuration key change as a note
- Add commit extlink to point at the relevant modification revision

OME-DCO-1.1-Signed-off-by: Sebastien Besson <seb.besson@gmail.com> (github: sbesson)
Rewrite section about corrupt index

- Add clear note about upgraded 4.4.x servers
- Do not mention loosely defined "corrupt" index
- Add reference to troubleshooting

OME-DCO-1.1-Signed-off-by: Sebastien Besson <seb.besson@gmail.com> (github: sbesson)
Rename re-indexing monitoring section

OME-DCO-1.1-Signed-off-by: Sebastien Besson <seb.besson@gmail.com> (github: sbesson)
Implement formatting suggestions by Petr

OME-DCO-1.1-Signed-off-by: Sebastien Besson <seb.besson@gmail.com> (github: sbesson)
Address Simon's comments

OME-DCO-1.1-Signed-off-by: Sebastien Besson <seb.besson@gmail.com> (github: sbesson)
Merge pull request #828 from sbesson/rebased/develop/percent_indexed

Search page tidying up (rebased onto develop)