
diskdb was a experimental attempt to track errors per DIMM
on disk. It ran into problems unfortunately.

diskdb is not compiled by default now. It can be enabled with 
make CONFIG_DISKDB=1

It is replaced with a new memory only database now that
relies on daemon mode.

Open fundamental issues:
- DIMM tracking over boot doesn't work due to SMBIOS not reporting
serial numbers

Code problems:
- Missing aging
- For Intel Nehalem CE errors need reverse smbios translation
- SMBIOS interleaving decoding missing
- Some crash races in db.c (see comments there)
- Need lock timeout
- Default enable/disable heuristics (smbios check etc.)
- write db test suite (with crash)

General:
- Missing CPU database

Missing:
- rename to different name without memory

Old:
- add ifdef for memory because it's broken
