Python bindings

[cberner]

• Change example in the readme on PyPi to be in Python

For Python bindings we'll want to support opening a database concurrently from multiple processes.

Reads from the metapage will need to be atomic without relying on the current Mutex. One idea is to add a nonce to each write as a header & footer, maybe generated from PCG or Lehmer Generator

Further reference: https://lemire.me/blog/2019/03/19/the-fastest-conventional-random-number-generator-that-can-pass-big-crush/

[yaofan]

Hi, is there any processing?