Added deep_crypt function.

Can now call deep_crypt to "deeply encrypt" a given file.  I think the
next step is to add a way to make this an option for the bundle
function, as that might be very useful.
Update to stex.sh and ssh config.

Changed ssh config policy to be one host per entry.

Changed stex.sh to handle shell escape.

BE AWARE OF SECURITY IMPACT OF THIS!