This will make a number of things easier in the future, as well as (finally!)
avoiding the Id-smashing problem which has plagued developers for so long.
Boy, I'm glad we're not using sup anymore. This update would have been
insane otherwise.
- don't #include other headers just to get struct names.
- don't use __BEGIN_DECLS/__END_DECLS for system prototypes. It is for
user prototypes.
- don't use extern.
- don't use lines longer than 80 columns.
- use alphabetical order.
- use tabs.
Uniformized idempotency ifdefs.
