freeipa/daemons/ipa-kdb

This is the ipa krb5kdc database backend.

As the KDB interfaces heavily with krb5, we inherit its code style as well.
However, note the following changes:

- no modelines (and different file preamble)
- return types don't require their own line
- single-statement blocks may optionally be braced
- /* and */ do not ever get their own line
- C99 for-loops are permitted (and encouraged)
- a restricted set of other C99 features are permitted

In particular, variable-length arrays, flexible array members, compound
literals, universal character names, and //-style comments are not permitted.

Use of regular malloc/free is preferred over talloc for new code.

By and large, existing code mostly conforms to these requirements.  New code
must conform to them.