Patched support for connections

Merge pull request #15 from evosch/patch-2

Update DatabaseQueue.php

Add support for connections

Add support for multiple connections

FIX: readme

Update readme to 0.5.* release

FIX: queue timestamp set on retry

FIX: queue timestamp set on retry

Timestamp db set fix

Fix of db timestamp fix.

FIX: Artisan command queue:database is missing an argument (queue name)

FIX issue #12
Artisan command queue:database is missing an argument (queue name)

Bugfixing in previous release

Bugfixing in src/Connectors/DatabaseConnector.php

Concurrency safe release

Thank's to @anedisi a concurrency listener safe release.

Fixed queue name in failed jobs table

Fixed queue names not being set in failed jobs table (code plucked from Laravel 5).

Thank's from @furey

Untangle from SyncJOb and psr-2 coding style

From great @svensp work:

• Grouped the where statements in DatabaseQueue::pop for state 'waiting' and 'open'. ungrouped it selected all jobs in state 'waiting', without regard to queue and timestamp
• Switched baseclass from SyncJob to the underlying abstract Job, as all SyncJob methods have now been overriden.
• Fixed release Before: Set state to waiting, then delete the job. Now: Set state to waiting, set Timestamp to now + $delay seconds, set Flag so the job won't be set to finished after running, increment retries
• Fixed attempts Now returns $model->retries + 1 instead of a static 1
• Fixed getJobId Now returns $model->getKey() instead of ''
• Added getRawBody This is my best guess to what this method should do. It seems to return the raw json payload in other implementations, so $model->payload seems right

Fixed PSR-2 compatibility with "php-cs-fixer".

Updated README.md