Fix Silverpop import test

Mock the disconnect method too, so it doesn't try to call the
original

Change-Id: I6fbf5103a2e28f5d44f573183479190806592e2c
Fix wmf_donor hook when editing contributions

Contributions object provided to the hook has only the changed
properties.  This patch will retrieve all necessary data if anything
is missing.

Change-Id: Ibce6c5f4419d248ba4f8e155ff5bf110a0c5857d
Merge branch 'master' into deployment

b103be3 Fix wmf_donor hook when editing contributions
9ed4a5b Fix Silverpop import test

Change-Id: Id1d9217e87e9e9132d9b292c81901bfc75184c59