Converting a public PEM-file to OpenSSH public file format

[Lars Nordin]

Hi,

I have made a new option i ssh-keygen, to read a public key in 
PEM-format and write a public key in openSSH-format. This file can be 
used to make the authorized_keys file.

I needed this function because I made an openssh-client where the 
private key in a smartcard and therefore not available for ssh-keygen to 
make the public file..

I can make a patch for this if anyone is interested!

/Lars