updated throughout to match latest MX Convention Attributes (1.0.4)

All significant attributes have comments and indicators of their source
(/N/=NODC, /C/=CF, /A/=ACDD). Many unneeded attributes deleted.
Attributes are ordered consistently with MX Priority column in
Convention spreadsheet
(https://docs.google.com/a/marinexplore.com/spreadsheet/ccc?key=0AmhiuQZ
YDrwtdE1QSTBycHVLWTVlTy1nUXhQVzlOZ1E&usp=drive_web#gid=0)

TODOs remain, mostly for Rob.