Fix path separator bug. The command line converts path into local
filesystem paths, then uses that to build server-side paths. This fixes
the slashes to the format used on the server, even if the client uses a
different format .(E.g.  Windows uses a backslash.)

Removed two known issues:
Doesn't work on Windows. But it does, though there may be some bugs.
It does handle files which have the same name on the server. In a crude
if functional fashion (errors out, or renames server-side).

Various yes/no promptes use Y/N but don't specify that the default is Y
(yes). Change them to indicate that in the customary manner for command
line programs, also used elsewhere in this program.

prompt: add a space in "Proceed with the changes? [Y/n]:"

README: fix s/hypen/hyphen/g plus deinitialization spelling

Ensure that nil is properly sent back after remote
change/file resolution. This regression was caused
by forgetting to send back that nil.

This regression was caused by PR
odeke-em#741.

The consequence of the bug was that trying to push
from non-existent folders would erraneously give
back
```shell
Resolving...
Everything is up-to-date.
```

since the remotesChan channel would get closed
after resolution without sending notifying
whoever was resolving that the file or parent didn't
exist remotely.

Fixes odeke-em#933

Fix path separator bug. The command line converts path into local
filesystem paths, then uses that to build server-side paths. This fixes
the slashes to the format used on the server, even if the client uses a
different format .(E.g.  Windows uses a backslash.)

Removed two known issues:
Doesn't work on Windows. But it does, though there may be some bugs.
It does handle files which have the same name on the server. In a crude
if functional fashion (errors out, or renames server-side).

Various yes/no promptes use Y/N but don't specify that the default is Y
(yes). Change them to indicate that in the customary manner for command
line programs, also used elsewhere in this program.

Update readme to be more accurate.

# Conflicts:
#	README.md