[DO NOT MERGE] fix bug 1075700 - add crypto pass-through crash store

r? @lars - @peterbe and @lonnen should look too if you have time.

Putting up for review/discussion, but please don't merge yet pending some further investigation of the ```simple-crypt``` package being used here.
@twobraids what about ```close()``` and ```remove()```, there's no encryption work to be done there, can I just not implement those too?