Fixes an issue in UnzstdStream where the Read() method always tries to
read new input data if no input data is available, instead of first
trying to uncompress. Since zstd maintains internal buffers,
uncompression might succeed even without reading more input, so this
is faster. This bug can lead to pipeline stalls in cdc_rsync.
Makes ServerSocket multi-platform, mainly by working around some small
API differences. The code is largely the same, there should be no
differences on Linux.
Also moves WSAStartup() and WSACleanup() up to the Socket level as
static methods because it's used by both ClientSocket and ServerSocket,
and because it doesn't make sense to do that in the socket class as
that would prevent one from using several sockets.
The tools allow efficient and fast synchronization of large directory
trees from a Windows workstation to a Linux target machine.
cdc_rsync* support efficient copy of files by using content-defined
chunking (CDC) to identify chunks within files that can be reused.
asset_stream_manager + cdc_fuse_fs support efficient streaming of a
local directory to a remote virtual file system based on FUSE. It also
employs CDC to identify and reuse unchanged data chunks.
