feat req: Allow user to specify shell on connect

[lachlan2k]

Allow a user to specify the shell when they connect. E.g. connect --shell=/bin/zsh foo.bar and connect --shell=/bin/bash foo.bar.

Eventually, this could re-open the door to allow the embedding of things like Busybox. So, a user might be allowed to embed my-favorite-sh into the client binary, and run connect --shell=my-favourite-sh foo.bar. The RSSH client would then execute this in-memory.

[NHAS]

Will do chief

[NHAS]

This is now on the unstable branch. Go ham

[lachlan2k]

poggies