Minor bug fix.
By creating a pretend MSYS/MinGW home directory for the current user, we
can avoid repeated warnings from SSH about not being able to update
~/.ssh/known_hosts.  We need to be careful to avoid copying the developer's
pretend MSYS/MinGW home directory when bundling for Windows, which is why
we use "rmtree" in packageWindowsVersion.py
The SSH Control Master / Control Path stuff which worked well on Mac OS X
doesn't work on Windows, so we're reverting to the old Upload methods which
do work.