openkal-musl 0.3.1

Supersedes 0.3.0, whose manifest named the implementation of openkal for each system
by a path. That is right in a working tree that has the repositories side by
side and wrong in a package: a path names a directory that exists where the
manifest was written and nowhere else, so a consumer resolving it from the index
was handed a dependency pointing into the registry's own store.

-openkal-linux = { path = "../openkal-linux", features = ["standalone"] }
+openkal-linux = { version = "0.5.1", features = ["standalone"] }

The feature travels beside the version, because a program above this library
carries no other runtime and that is what the feature states.

Found by resolving the package the way a stranger would, from a store with every
local copy deleted. A working tree masks every mistake in a manifest's
dependencies, because the tree is what the manifest was written against.

The contents are otherwise those of 0.3.0; its release notes describe them.