[DOC] check: Add a note about parse_ini_file as it causes WSoD if disabled and you are using a System Configuration (ini) file.

git-svn-id: file:///var/local/code.tiki.org/tikisvn/branches/13.x@52661 b456876b-0849-0410-b77d-98878d47e9d5
[FIX] check: Add json extension as a requirement (thanks Gezza)

git-svn-id: file:///var/local/code.tiki.org/tikisvn/branches/13.x@52662 b456876b-0849-0410-b77d-98878d47e9d5