Append comment, if present, to the deletedrevision text. This matches undeletion behavior.
To pretty that up, removed the final period from the default deletedrevision message; it didn't look good with the following colon, and even when alone it's inconsistent with other usage, we usually don't have a period there.
* Making message 'sorbs' optional. It is untranslated/untranslatable in most languages.
* Removing http://www.sorbs.net from all messages. It was removed from MessagesEn.php in r17528 as it is no longer the DNSBL default.
* Renaming 'watchdetails' -> 'watchlist-details' incl. all localizations, some had still the old parameters $2-$4 (since ages removed from MessagesEn)
* Removing parameters $2 (seems useless/crap) and $3 (marked already as remove-TODO) from SpecialWatchlist.php and as stated above unsed since ages
* Removing 'watchall1' too, now unused
Make messages 'isbn' and 'booksources-isbn' optional as ISBN is untranslated in all latin and most non-latin script languages.
Removing theses messages from message files.
php -l says they're all fine, looking them over they seem to all be fine. Languages that already had this update individually have doubled entries, but that shouldn't make a difference and a run through rebuildMessages.php should fix if it annoys you.
* Created a new message, 'pagecategories', which is used instead of 'categories' in the categorylinks box under the articles.
* Duplicated 'categories' to 'pagecategories' in all the languages.
* Removed "{{PLURAL}}" from 'categories' (and not 'pagecategories'), as it's ignored when used as the title of Special:Categories, and was added for the categorybox which now uses 'pagecategories'. It makes no harm, but it's useless, as no parameter and "{{PLURAL}}" is used for 'categories' - only for 'pagecategories'.
