debuginstall: strip double quotes from editorbin on Windows
The unconditional posix style shlex.split() prior to
94a1ff16f362 handled this.
This isn't mutually exclusive with stripping the quotes in util.findexe()- if
the editor can't be found, this command prints out the string, inside single
quotes.
Set up
$ hg init repo
$ cd repo
Try to import an empty patch
$ hg import --no-commit - <<EOF
> EOF
applying patch from stdin
abort: stdin: no diffs found
[255]
No dirstate backups are left behind
$ ls .hg/dirstate* | sort
.hg/dirstate