Updated build scripts for sshd and Email

Updated build scripts for product.
Added sshd, scp, and sftp to VM modules.
Added custom sshd_config to VM.
Updated build script to read SVMP_AUTHORIZED_KEYS and copy file accordingly.
Added stock Email package to VM modules.
Ssh is now supported with public key authentication.
authorized_keys is copied at build time, see "build-svmp.sh" for instructions.