RFC: cleaning up the in-kernel headers

[Adrian Bunk <bunk@stusta.de>]

I'd like to cleanup the mess of the in-kernel headers, based on the 
following rules:
- every header should #include everything it uses
- remove unneeded #include's from headers

This would also remove all the implicit rules "before #include'ing 
header foo.h, you must #include header bar.h" you usually only see when 
the compilation fails.

There might be exceptions (e.g. for avoiding circular #include's) but 
these would be special cases.

As a side effect, this might also lead to additional cleanups.

This might cause some breakages, but it should usually only be compile 
breakages I'll fix as soon as I see them (or anyone else reports them 
to me).

My plan is to create a git tree where I'll work on this that will be 
included in -mm.

Is this OK for everyone?

cu
Adrian

-- 

       "Is there not promise of rain?" Ling Tan asked suddenly out
        of the darkness. There had been need of rain for many days.
       "Only a promise," Lao Er said.
                                       Pearl S. Buck - Dragon Seed