[PATCH] SourceFactor: remove CVS-id and extern

Hi,
the attached patch builds on the recent sourcefactor work. It:
- removes stale CVS $Id$ markers
- removes unnecessary "extern" function declarations
- removes all unneeded SQUIDCEXTERN declarations
- fixes a mismatching class / struct declaration for _fde_disk, and offers
a proper constructor for it, removing initialization in the caller

It is farm build tested.

-- 
/kinkie