* Mostly tightening up the details on the hkp4py example script.
* Also fixed a typo in the LGPL boiler plate text included in all the
other example scripts for the HOWTO.
* Similar to encrypt file except for signing a file in normal mode.
* Noticed additional changes to be made to the howto to match this,
but they will have to wait due to a power outage (currently running
on battery and a mobile connection, but that won't last).