added "One Time Password" support for ssh

you can now add an ssh auth with "add sshotp" command. server.js will
change the password, before make you able to access, with a random
string. That new password will be replaced with the original one, saved
in db.
Merge branch 'master' of https://github.com/ujaku/PAAM

Conflicts:
	clients/os/macosx.js