DVD support for cdrecord.

 This patch adds dvd writing support for cdrecord-1.11 version 1.11a08.
For your convenience, I've added a complete tarball of cdrtools with the patch included.
Doug Brott has updated the patch to be supported for version cdrecord-1.11a11. You can find his patch here.

- On DVD the only valid write modes are DAO (disk at once) and Incremental (packet).  Incremental writing on DVD-RW is only allowed when the
disk is new or it has been fully blanked . Minimally blanking the disk will only work if you want to use DAO.

- You have to use -dao or -packet option, because cdrecord uses TAO (track at once) mode by default.

- When writing in DAO mode cdrecord needs to know the size of the "track". If you want to get the input directly from mkisofs, you have to use first mkisofs's -print-size option:
    cdblocks=` mkisofs -print-size -quiet ... `
    mkisofs ... | cdrecord ... tsize=${cdblocks}s -
If you write an image from filesystem, you don't have to do that, cdrecord will take the file size.

-I observed that when you write a small quantity of data (<10MB) it needs a very long time to close the disc (about 15min).  This is because the lead out of the disk needs to be at some distance from its center and the drive needs to write up to that point.

 -Because cdrecord is broken in the sense that it thinks that packet -> TAO, I had to modify cdrecord such that incremental writing will work on DVD but it will probably not work on CD. Otherwise using -packet option would result in "drive does not support TAO writing mode" error (this is stupid).

Special Thanks to Keiji Katata from Pioneer, Japan and to Jack Ciao for helping me with this driver.

Please send me any bug you find.

Nicolae Mihalache