Break audit_bsm_klib.c into two files: one (audit_bsm_klib.c)
retaining various utility functions used during BSM generation,
and a second (audit_bsm_db.c) that contains the various in-kernel
databases supporting various audit activities (the class and
event-name tables).

(No functional change is intended.)

Obtained from: TrustedBSD Project
MFC after: 3 weeks
Sponsored by: DARPA, AFRL