v0.2.0

Changed

• tftp.path is built on pathapi and uripath. The path extra installs
  pathapi>=0.1.0,<0.2 and pathapi-uri>=0.1.0,<0.2 where it installed pathlib-next[uri],
  which cannot be installed beside them. To upgrade, import LocalPath, MemPath and FileStat
  from pathapi instead of pathlib_next, and spell the URI path
  from uripath import URIPath; URIPath("tftp://host/file") where it was
  pathlib_next.uri.UriPath. TFTPPath and TFTPURIPath keep their names, arguments and
  methods, and URIPath("tftp://...") finds TFTPURIPath without an import, now through the
  uripath.schemes entry-point group.
• unlink() always raises NotImplementedError. unlink(missing_ok=True) used to return
  without doing anything, so that copy(overwrite=True) could clear its target. pathapi no
  longer asks a target that cannot be removed to do that, and the write that follows still replaces
  the file, so a caller of copy() changes nothing. A program that called unlink(missing_ok=True)
  itself must stop, or ask pathapi.protocols.supports(path, Remove) first.
• move() from a TFTP path raises NotImplementedError before it copies anything. It used to
  copy the file and then raise because the source could not be deleted, which left a stray copy at
  the destination. Check supports(path, Remove) to know in advance.
• stat() says when the server gave no size. A server that does not send tsize (and a file
  longer than one block) used to give st_size == 0 as if it were known; the result now has
  size_known == False, and st_size is still 0. A caller that needs the size reads the file or
  uses a server that reports it.

Added

• pathapi.protocols.supports(path, Listing) answers for the server: one x-list probe of its root
  on the first question, kept for the life of the client, False for a server without the
  extension. The classes implement Stat, BinaryOpen, Listing, Identity and Copy, and
  capabilities() of either says so.

Fixed

• A failed or abandoned upload no longer replaces the server's file. A with block over
  open("w") that raised, a text write that could not be encoded (write_text("\u00e9", encoding="ascii")) and a file collected unclosed all uploaded what had been written, even an
  empty file. Each now sends nothing and the server keeps the file it had; a stream collected
  unclosed emits one ResourceWarning. Closing a stream normally still uploads.

Full Changelog: v0.1.1...v0.2.0