[jsword-devel] Support for locked modules

[DM Smith]

I have added support for locked modules and tested it against a soon to 
be released locked module.
I have not had much time to look at this module but at a glance, it 
looks very good.

To do this I implemented Sapphire II Stream Cipher by Michael Paul 
Johnson, which is used to encipher the modules.
I changed the code to support modules that have a CipherKey and complain 
about locked modules w/o one.
In order to do this, I had to get the cipher key down to the backend. So 
that took a bit of refactoring.

I have also changed our use of osis:seg for bold, italic and underline 
to use osis:hi.