Added an empty option to the choose server drop down in the AddLayersDialog
Un-fixed a bug that was fixed in commit 120cf13 on May 8th.  The bug allowed users to attempt to sync without a connection, and allowed Arbiter to successfully sync via a radio network even though the device did not consider it a proper connection.  We re-broke this to get it working on the same radio network again.  Hopefully we can implement a more graceful way to do this in future.
Removed a bunch of connection checks to enable more functionality over radio networks.
Added an option to the settings menu to toggle connection checks.  Currently this does not update the status of the status of the sync button though, so the app will need to be restarted after changing this setting.