0.0.1

Initial release.

Includes xvenv, a tool for creating cross platform environments. This has undergone initial testing to verify it works for iOS, Android and Emscripten environments. The created environment is sufficient to trick pip into installing binaries for the target platform into the environment; and for tools like wheel to trigger builds with compiler invocations derived from sysconfgdata. This won't generally result in a successful build, as there will usually be other environmental requirements; but the a cross-platform build will be attempted.