Change-Id: I516dc2aca05823add9daf8c6d4c4af7ef7d2a313

It is often quite useful to try to see what the contained causes
are on versions of python that do not have the native support for
this built-in so to make everyones life easier add basic support
for traversing the cause list and printing out associated causes
when we are able to.

Change-Id: Ia0a7e13757a989722291bcc06599d04014706d8c

In order to chain exceptions add a helper that can
be used to chain exceptions automatically (when able)
and use it in the various places we are already creating
a new exception with a prior cause so that on py3.x the
newly created exception has its 'cause' associated using
the syntax available to do chaining in py3.x (which formats
nicely as well in that python version).

Change-Id: Iffddb27dbfe80816d6032e4b5532a0011ceedc95