Log execution phase and include information

We pass the execution phase and the index of the phase now, so emit it
into the play banners in the log. This will allow us to post-process the
logs and put in smart things like "collapse pre tasks".

Also include information about include statements.

Also rename zuul_execution_phase_count to zuul_execution_phase_index -
mainly just because it's an index not a count. My shed is red.

Change-Id: I975ed9547bbcdbb70d5a25c9be398888bdcdb07a
2 files changed