• Fixed resolveBackendConfig not checking options
• Removed old _InMemory
• Removed getMount and getMounts
• Exported mounts
• Removed FileIndex (moved to dom)
• Fixed Overlay options being options
• Renamed OverlayFS.ts to Overlay.ts
• Changed AsyncStoreFileSystem to allow passing in an AsyncStore not wrapped in a promise
• Fixed metadata getter on SyncStore and AsyncStore
• Added ReadonlyAsyncFileSystem and ReadonlySyncFileSystem