This fixes a bug where ggatessh was consuming 100% cpu because the
error from sftp_open wasn't being checked, now ggatessh will exit
if this fails (and log the failure)...

Add a test to make sure that a second session is launched and
works..  This discovered that the sftp_open wasn't passing in the
correct file name...

Now that there will be multiple IOs in flight, this should improve
performance a bit...

This gets things working sanely for packaging...

Also did some line wrapping..

git-subtree-dir: libssh2
git-subtree-split: 6c7769dcc4

a patched version that does not do read ahead.  It also supports
resizing when rescuing and the file has changed sizes..

the performance is ok, but likely can be improved upon:
libcurl seems to not reuse connections, why not?
libcurl when using any auth, ALWAYS tries unauth'd for EVERY
  request instead of caching that this url NEEDs auth
there are some error handling cases that could be improved

This isn't the best as it depends upon a WebDAV server already running..

It uses additional threads to have more IOs inflight.  This
should be useful for devices, but likely not for files.

for communication instead of TCP.  This allows you to forward the
connection over ssh in a secure maner.  Though you can forward TCP
sessions over ssh, it doesn't implement authentication, so ANYONE
on the box could end up accessing the disks.  With socks you can use
file system permissions to restrict them.