Use timeutils.utcnow() throughout the code
Use timeutils.utcnow() throughout the code

timeutils.utcnow() should be used instead of direct calls to
datetime.datetime.utcnow() to make it easy to override its return
value in tests.

Add a hacking rule to prevent regressions.

Fixes bug 1200141.

Change-Id: I170dbd7c9093bd627e2a0d5984b7ad1bf105c8d5

n0ano/gantt,n0ano/gantt