Enable sandbox

[imanel]

This will require disabling Media Keys.

Required entitlements:

• com.apple.security.app-sandbox
• com.apple.security.network.client
• com.apple.security.files.user-selected.read-only (for file upload)

Detecting sandbox: http://www.cocoabuilder.com/archive/cocoa/312065-determine-sandbox-entitlements-at-runtime.html#312086