Add a persistence util logbook formatting function

It is quite useful to be able to dump what is in a
logbook in a human readable format so this adds a
helper utility function to do just this.

Change-Id: I84d8a9caf531de018fb361211624fc5b8c030260
Pattern comment additions/adjustments

Change-Id: I3154d1c228474d8699f3ae4d0be2fb46406a2f41
Beef up the action engine comments

Also make a few minor tweaks to the
underlying functions and relax the
networkx requirement slightly.

Change-Id: Ibbfa7f786d3c33956f7ca39b7ea9423696859e45
Comment additions for exponential backoff

Change-Id: If43d6e5ceedc17b1763ecd8a244f959150b802e1
Merge "Add a persistence util logbook formatting function"
Merge "Beef up the action engine comments"
Merge "Comment additions for exponential backoff"
Merge "Pattern comment additions/adjustments"