REVIEW-2992 DefaultCacheAccess.seek instead of skipBytes.
REVIEW-2968 the file lock manager now also writes 'owner id' to the state region of the lock. This way, we will know whether the lock was 'touched' by some different process, and we could base in-memory cache expiration strategy on this information. The 'clean' flag is replaced with the new owner id information (e.g. ownerId == 0 means the cache is dirty).
Because the file lock protocol has changed, it is necessary to bump the artifact cache.
Refactoring in the file lock manager, added method to read the previous owner id.
File lock now knows if has it has a brand new owner process, or it was acquired by the same process.
Refactored a bit the default cache access so that it is easy to decorate the caches with in-memory caching capabilities.
Extracted MultiProcessSafePersistentIndexedCache interface.
Checkstyle
Inlined 2 collections into one.