If failed lookups are fatal, re-raise the exception

Fixes #1938.
proper bin path now called
Merge pull request #1939 from diefans/devel

proper bin path now called
Fix get_url to work on Python 2.4
- make extra-vars override all other vars and facts in playbooks
Only inventory "running" EC2 instances. "stopped" is also a valid state and these should not be inventoried.
Merge pull request #1946 from tgerla/devel

Only inventory "running" EC2 instances. "stopped" is also a valid state ...
stop updating SETUP_CACHE in run_play as per comment on pr 1945
Merge pull request #1945 from skvidal/extravars

- make extra-vars override all other vars and facts in playbooks
Fix error format for invalid vars_files