Remove upgrade note from the server upgrade page
Differentiate DB upgrade step between 4.4.x and 5.0.0-beta1 servers
Add section about JCM memory settings
Remove temporary server-migration-fs page
Add documentation for password provider changes to support salting

This commit modifies the sysadmin and developer documentation to document
the latest changes to the password provider including pasword salting support.
Fix the DB upgrade command for 5.0.0-beta1
Rewrite optimization lines to include quotes as tested in the job
Try to improve the sentence about reverting salting
Minor fixes to the server upgrade page
Fix dot in password provider page
Remove duplicated links from the sysadmin index page
Exchange "Link" for user-friendlier "Mix data" cf. Gus's comment
update plugin options. See #11806
Merge remote-tracking branch 'origin/develop' into 11787_server_upgrade
Add note to What's new page about password salting
Merge pull request #576 from sbesson/11787_server_upgrade

Review server upgrade and password provider pages
Merge pull request #582 from will-moore/web_plugin_update_11806

update plugin options. See #11806
Merge pull request #580 from pwalczysko/fix-permissions

Exchange "Link" for user-friendlier "Mix data" cf. Gus's comment