Add Bourne style quoting for TransportGitSsh
Now that we have a nice QuotedString abstraction we can port our
string quoting logic from being private within the SSH transport
code to being available in the rest of the library.
Currently we only support the super-restrictive quoting style used
for the repository path name argument over SSH. We don't support the
"minimal" style used to invoke the command name, nor do we support
the ~user/ style format, which cannot be quoted.
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Robin Rosenberg <robin.rosenberg@dewire.com>