langpacks/english: manual update according commit [6898]

git-svn-id: http://svn.miranda-ng.org/main/trunk@6929 1316c22d-e87f-b044-9b9b-93d7a3e3ba9c
langpacks: update according to commit [6929]

git-svn-id: http://svn.miranda-ng.org/main/trunk@6930 1316c22d-e87f-b044-9b9b-93d7a3e3ba9c
Db_autobackups: minor cleanup

git-svn-id: http://svn.miranda-ng.org/main/trunk@6931 1316c22d-e87f-b044-9b9b-93d7a3e3ba9c
Facebook: use TCHAR* instead of char* on many places (chat related)

git-svn-id: http://svn.miranda-ng.org/main/trunk@6932 1316c22d-e87f-b044-9b9b-93d7a3e3ba9c
Facebook: Added hidden option to keep messages unread (as requested by Guenter Gruene)

Add byte key "KeepUnread" with value 1 to account settings or to particular contact

git-svn-id: http://svn.miranda-ng.org/main/trunk@6933 1316c22d-e87f-b044-9b9b-93d7a3e3ba9c