Added icons for iOS. Broke out data access into repositories. Added syncing service.

src/App/Abstractions/Repositories/IFolderRepository.cs

@@ -0,0 +1,12 @@
+using System;
+using System.Collections.Generic;
+using System.Threading.Tasks;
+using Bit.App.Models.Data;
+
+namespace Bit.App.Abstractions
+{
+    public interface IFolderRepository : IRepository<FolderData, string>
+    {
+        Task<IEnumerable<FolderData>> GetAllByUserIdAsync(string userId);
+    }
+}