188.8.131.52: close the fd before deleting / moving files on CLOSE :ABORT T
* Windows is not happy about files with open handles dancing around.
This should one of the SB-COVER problems on Windows, and is
arguably better for posixoid platforms as well.
* SET-CLOSED-FLAME immediately after closing the fd, since that is in
a very real sense the boundary after which doing stream operations
is going to lose.
* Windows additions to .gitignore.