API TradeItSDK.launcher.launchAccountSelection needs prepopulated account

[imougy]

In order to allow users to change what they sync (from one account to another), we need to display the selection controller with an already selected account if any. I identify the accounts by accountNumber in my data model.

Also, the cells need to have a checkmark accessory UITableViewCellAccessoryCheckmark, not the current UITableViewCellAccessoryDisclosureIndicator.