Revise comment deletion message.


git-svn-id: http://opensvn.csie.org/pttbbs/trunk@6018 63ad8ddf-47c3-0310-b6dd-a9e9d9715204
Alert when no available comments data.


git-svn-id: http://opensvn.csie.org/pttbbs/trunk@6019 63ad8ddf-47c3-0310-b6dd-a9e9d9715204
Alet when pvcm deletion falied.


git-svn-id: http://opensvn.csie.org/pttbbs/trunk@6020 63ad8ddf-47c3-0310-b6dd-a9e9d9715204
Revise pvcm welcome messages.


git-svn-id: http://opensvn.csie.org/pttbbs/trunk@6021 63ad8ddf-47c3-0310-b6dd-a9e9d9715204