WfBuf rust crate

This crate allow to create mmaped shared anonymous regions of memory, place WfBuf into it and use it for data streaming between parent and forked child process. Work only on linux.

Implementation is naive and may be unsound. Stricly for one reader and one writer. There is no queueing, only last written value is read. Implementation trying to ensure that to the moment of reading value is the lates written. You can see how it may be used in tests module in lib.rs.