Misc enh and few fixes.

DRY:
+ Removed duplicated try: .. except Exception:
  set_value("UNKNOWN: Trigger error".., 3)
  it's now catched by shinken trigger.py itself.

+ few fixes.
Add: use trigger_broker_raise_enabled by default in template.
Merge pull request #1 from savoirfairelinux/fix_triggers_v1

Fix triggers v1