Editor updates to Device Support Extensions binding Document, Version 0.7.

• Page 3, lines 1-24: Added Introduction, Purpose and Scope Sections.
• Page 3, lines 39-44: Added References [4], [5] and [6].
• Page 4, lines 22-23: Changed the wording from 'In addition to the Open Firmware Standard 'open', 'close', and 'read' methods, the following mehtods "shall" be supported by an Open Firmware implementation of a "keyboard" device' to 'Keyboard devices "shall" implement 'open', 'close' and 'read' methods as defined by the Open Firmware standard[1]'. Removed 'keyboard' methods ('get-scancode', 'scancode->char' and 'set-language') from Section 3.2.
• Page 8, Section 8.: Added Serial Port Device Section.
• Page 10, lines 34, 37, 41, 42, 44, 50: Changed 'SCSI' to 'SCSI-2'.
• Page 11, lines 7, 10, 15, 22 & 34: Changed 'SCSI' to 'SCSI-2'.
• Page 12, line 46: Added 'serial' to '/alias/ Node properties'.