cylc/cylc#204: suite environment file.

* Write file at submit time.
* Use for messaging.
* Reinstate at restart for hosts with submitted/running jobs.
Reset held tasks to waiting on restart.
Don't update task elapsed time if start time not set.
Set running tasks' started output completed on restart.
Renew the pyro proxy get in message retry loop.
Merge pull request #1 from hjoliver/204.suite-env-file

204.suite env file
Merge branch 'master' into 204.suite-env-file
Merge branch 'master' into 204.suite-env-file

Conflicts:
	lib/cylc/task_message.py
	lib/cylc/task_state.py
Tidy up missed syntax in conflict resolution.
Merge branch 'master' into 204.suite-env-file
Merge branch 'master' into 204.suite-env-file
Merge branch 'master' into 204.suite-env-file

Conflicts:
	lib/cylc/job_submission/job_submit.py
	lib/cylc/scheduler.py
Bring branch up to date with global config changes.
Merge pull request #2 from hjoliver/204.suite-env-file

Bring branch up to date with global config changes.
suite environment file: relocate to run directory.
suite environment file: fix restart host select syntax.
suite environment file: fix syntax.
suite environment file: correct syntax for scp.
Fixed recent bug in task.cylc_env

The task class cylc_env dict was being modified slightly by each task
instance. Each task re-alters it appropriately, but some a chance of
race condition type error?
job file: add TZ=UTC in UTC mode.