Item12891:Item11844: general rewrite

also:
- add modes to operate on individual topics only
- by default ignore some file names of auto-generated files and thumbnails



git-svn-id: http://svn.foswiki.org/trunk/UpdateAttachmentsPlugin@17652 0b4bb1d4-4e5a-0410-9cc4-b2b747904278
Item12891: preparing release



git-svn-id: http://svn.foswiki.org/trunk/UpdateAttachmentsPlugin@17653 0b4bb1d4-4e5a-0410-9cc4-b2b747904278
Item12839: require authentication calling the rest handler


git-svn-id: http://svn.foswiki.org/trunk/UpdateAttachmentsPlugin@17654 0b4bb1d4-4e5a-0410-9cc4-b2b747904278