Supply Path.Combine method, or auto-convert backslashes

Since .Net follows Windows' path rules, using System.IO.Path.Combine to build up a directory structure creates a path full of backslashes.

It would be helpful if either SSH.Net were able to auto convert backslashes to forward slashes before contacting the server... however I believe it's possible to use a backslash as a valid character in the file/directory name on some systems; thus if this were provided there should be an option to disable this behavior.

Safer, if a Renci.SshNet.Path.Combine method were provided it would give users an easy way to build valid paths, without having to reinvent the wheel each time.

Esamina i due approcci proposti nell’issue: una conversione opzionale delle barre rovesciate in barre oblique oppure un metodo Renci.SshNet.Path.Combine. Determina quale comportamento dovrebbe essere supportato e in che modo le barre rovesciate valide nei nomi remoti lo influenzano. Il lavoro è completato quando gli utenti possono creare percorsi remoti validi senza reinventare ripetutamente questo comportamento.