Auto-update RESTClient releases

[subwiz]

Would love to start pushing updates instead of announcing updates.

[subwiz]

In-app notification of new version availability is added. Commits on date Oct 02, 2014.

[juergenzimmermann]

Is there an Option to switch off this new feature?

[subwiz]

To disable: add update.check.enabled = false to ~/.rest-client/rest-client.properties. Disable from the UI is not added as of now. The check happens once in 7 days only.