Revert "Revised Main_toggleUnreadMark()"

This reverts commit 225514c9813a6ff4ecc49888f808486c061d35fc.
Revert "Revised Main_markEntryRead()"

This reverts commit 5c14e466aaef1afff7e5f1d6a12627c337e181ab.
Revised Main_markEntryRead()

regarding the removed Main_markEntry(e, f, flag)