Added rescue to prevent crashing on Windows

'unsupported signal SIGUSR1' occurs when running on Windows. SIGINT is supported in Windows and the rest would be ignored.
Fixes a race condition which could result in a scheduled item being added to the queue twice, or a retry being retried twice.
Removes unnecessary transaction.
Merge pull request #1496 from mperham/feature/multi-to-mget

Removes unnecessary transaction.
Merge pull request #1495 from mperham/feature/race

Fixes a race condition which could result in a scheduled item being adde...
Merge pull request #1494 from Jellyfishboy/master

Added rescue to prevent crashing on Windows
Fix sidekiqctl pidfile issues, fixes #1490
bump ver