This moves MemoryMount to the main core module, and converts it to be a
"proper" WritableMount. It's still naively implemented - definitely
would be good to flesh out our tests in the future - but enough for what
we need it for.
We also do the following:
- Remove the FileEntry.path variable, and instead pass the path around
as a variable.
- Clean up BinaryReadableHandle to use ByteBuffers in a more idiomatic
way.
- Add a couple more tests to our FS tests. These are in a bit of an odd
place, where we want both Lua tests (for emulator compliance) and
Java tests (for testing different implementations) - something to
think about in the future.
This adds SPDX license headers to all source code files, following the
REUSE[1] specification. This does not include any asset files (such as
generated JSON files, or textures). While REUSE does support doing so
with ".license" files, for now we define these licences using the
.reuse/dep5 file.
[1]: https://reuse.software/
