Fix: logger_class can be undefined.
Merge pull request #741 from ifduyue/logger_class_bug

Fix: logger_class can be undefined.
Move setting of environmental variables before preload_app start.

Move setting of env vars from Arbiter.start to Arbiter.setup so that they are available during application start up when 'preload_app' is used.

Closes #735
Merge pull request #740 from tshlabs/735-envvars-preload

Move setting of environmental variables (configured via the raw_env sett...