Box Backup

Reset NamedLock? file descriptor immediately after closing. Otherwise, if we fail to unlink the lockfile, we will try to close it again, which will fail because it's already closed, and we'll never get around to unlinking it.

Whitespace, layout and comment cleanups.

Add configurable timeouts and HEAD request support to S3 client. Allow getting the Content-Length of an HTTPResponse object.

Improve exception handling on backup store side. Add a new exception code to represent an object being completely missing (not found on the store at all), separate from not being found in a particular directory. Improve mapping of server-side ... [More] exceptions to protocol error messages returned to the client. Add handling for missing exceptions, such as BackupStoreException::PatchChainInfoBadInDirectory?, and the new BackupStoreException::ObjectDoesNotExist?. Fix mapping for BackupStoreException::CouldNotFindEntryInDirectory? to make it distinguistable from BackupStoreException::ObjectDoesNotExist?. [Less]

Fix memory leak tracking of calloc() allocations

Add a BackupStoreFile? encoding streaming verifier

Allow moving a CollectInBufferStream?'s contents to another one

Allow releasing a MemoryBlockGuard?

Whitespace cleanup

Fix random failures of testbbackup test_backup_pauses_when_store_is_full. Stop the client while waiting for housekeeping, to ensure that it doesn't prevent housekeeping from running and cause the test to fail.