remove init::headers

[James E Keenan]

Will Coleda wrote:
> Can anyone see a reason why we have a config step (init::headers) to
> generate this list of files? Looks like it's just grepping  through
> the MANIFEST to find them -
>
> They are then thrown on the "big pile" of headers in GENERAL_H_FILES,
> and (incorrectly) in the PMC dependencies. Even if they were used
> correctly, there's no reason to generate the list dynamically.
>
> Unless someone sees some value here, I'll rip this out in a branch.
>

I'll try to take a look at this within the next few days.

kid51