Cached registry key information can become inconsistent

We're missing several calls to CmpCleanUpSubKeyInfo, which means the cached information gets out of sync.

Calling CmpCleanUpSubKeyInfo in DoCreateKey initially fails because of missing locking. I've partially implemented this locking, but it turns out my rudimentary KCB array is not enough. We need CmpComputeHashValue/CmpBuildAndLockKcbArray, which parse the keyname, precompute all hashes for the key path components, and lock the appropriate hash entries.