Please add IdentityKey passphrase support #29
Description
It's great that Pubkey auth support has been added, but it would be even greater if it supported also these with the Passphrase. Now I have to strip off all of the passwords from my keys to use them. For example Ghost Commander has it the way that if a key file is specified, the password field has the IdentityKey passphrase function, maybe it could be applied here too? Thank you.