Merge pull request #605 from will-moore/small_fixes_from_PR603_develop

Small fixes from PR #603
Merge pull request #628 from hflynn/rebased/develop/rebased/dev_5_0/webplugin_tidy

Tidying webclient plugin page (rebased onto dev_5_0) (rebased onto develop)
Merge pull request #606 from sbesson/rebased/develop/server_upgrade_bugfix

Server upgrade bugfix (rebased onto develop)
Fix hardcoded links to Javadocs in the developer documentation
Add parenthesis to method names
Clarify instructions for rebuilding download page
Clarify user help website update
Add stats spreadsheet update to the post-release items
Rename latest-virtualbox jobs
merge develop -D org -I include -E exclude: PR 594 (Blitz api5 11852)
merge develop -D org -I include -E exclude: PR 596 (document extra values for omero.fs.repo.path_rules (ticket #10822))
merge develop -D org -I include -E exclude: PR 623 (Add forgotten items from previous releases to the release process page)
merge develop -D org -I include -E exclude: PR 626 (Add new Squash tutorial and screenshots)
merge develop -D org -I include -E exclude: PR 629 (Update renamed stable jobs in continuous integration page)
merge develop -D org -I include -E exclude: PR 630 (Fix hardcoded links to Javadocs in the developer documentation (rebased onto develop))