Cleanup setting fast abort
Adds count of tasks with missing stdout, input or output files.
Fast abort only consider average with succesful tasks.
remove dangling stats->total_tasks_failed
Use only execute and transfer time of succesfull tasks
Add flag to recognize foreman more easily
Do not fast abort foremen
Merge pull request #391 from btovar/fast_abort_mods

Fixes for WQ fast abort:
1. Use average of the running time of successful tasks when doing fast abort.
2. Don't fast abort a foreman.
Treat disk available as inuse
Measure foreman disk at intervals
Merge pull request #395 from btovar/foreman_measure_disk

Measure available disk space at foreman at periodic intervals (10s).
Allow more than 1024 characters in nvpair_print_malloc

With workers running more than one task, the current tasks sent to
wq_status -W may use more than 1024 characters, causing a master segfault.
Check for gpus only once.
Compute total disk and memory according to available and inuse.
Merge pull request #398 from btovar/gpu_only_once

Check for gpus only once.
Add commit and reap tasks functions to/from workers
Integrate commit/reap functions
Do not allow labeled/unlabeled to mix
Simplify workers_to_wait conditional
Pull poll-links out of wq_wait_internal