Raw block device as a backend #33

I would like to be able to use a raw block device (i.e. a partition or an entire drive) as a backend for this library (like how it is supported by e.g. InnoDB engine). Support for different block sizes (at least powers of two, in bytes, starting from 512) is expected, as well as optimized storage format/scheme which would potentially reduce serialization/deserialization time, unnecessary I/O operations and fragmentation specifically for these devices. Preferably if the level of reduction is analogous to that of Cap'n Proto for serialization-based tasks, without significant loss of capabilities.

I'd be glad to hear of opinions on, particularly, estimated amount of research which needs to be performed for this task to be reasonably claimed to be achieved.

Also, in the perspective I would like the library (or at least the core part of it) to be independent from Rust's std crate, so that it could be used on freestanding environments, such as unikernels for Xen paravirtualization.