Port iText core revision 6407 (DEV-793 Hanging of tab logic in case overflow.).
Added missing tests in ChunkTest.

git-svn-id: svn://svn.code.sf.net/p/itextsharp/code/trunk@768 820d3149-562b-4f88-9aa4-a8e61a3485cf
Port iText core revision 6410 (Use Unicode for named destinations).

git-svn-id: svn://svn.code.sf.net/p/itextsharp/code/trunk@769 820d3149-562b-4f88-9aa4-a8e61a3485cf