[FIX] listpages plugin: Restore missing category processing code, fix version/s typo and make for_list_pages param default to 'y' (so backlinks get shown)

git-svn-id: file:///var/local/code.tiki.org/tikisvn/branches/11.x@47745 b456876b-0849-0410-b77d-98878d47e9d5