Respect PHP's configured error reporting.

The Gearman custom error handler previously handled all error types
regardless of the configured error_reporting value.
Merge branch 'fix-gearman-error-handler' into add-redis-module
Fix conditional.
Merge branch 'fix-gearman-error-handler' into add-redis-module
Improve connection handling in Redis module.

Now does a lazy connect and maintains connected/disconnected status when
running commands.