cli: Fix --devid parameter

This wasn't actually setting the device ID for decryption, so the user
would need to omit --devid and enter it manually.

Signed-off-by: Kevin Cernekee <cernekee@gmail.com>
Remove IMEI references

The RSA device ID is not the same as the IMEI on many soft token clients.
Most users will probably need to obtain this number from the official RSA
app.

Signed-off-by: Kevin Cernekee <cernekee@gmail.com>
Support device-locked tokens deployed to smartphones

For iPhone/Android/"mobile" format token strings, the device ID is
encoded a little bit differently.  Prior to this change, stoken would not
successfully decrypt (or export) such a string.

fixes #1

Signed-off-by: Kevin Cernekee <cernekee@gmail.com>