I've often found it useful that you can make symlinks to Unix-domain
sockets, and then connect() on the symlink path will redirect to the
original socket.
This commit adds an option to Unix Pageant which will make it symlink
its socket path to a link location of your choice. My initial use case
is when running Pageant in debug mode during development: if you run a
new copy of it every few minutes after making a code change, then it's
annoying to have it change its socket path every time so you have to
keep pasting its setup command into your test shell. Not any more! Now
you can run 'pageant --debug --symlink fixed-location', and then your
test shell can point its SSH_AUTH_SOCK at the fixed location all the
time.
There are very likely other use cases too, but that's the one that
motivated me to add the option.
94a756f3a9