Add DateFormat to async conneciton

Author: praeclarum

src/SQLiteAsync.cs

@@ -101,6 +101,12 @@ public SQLiteAsyncConnection (SQLiteConnectionString connectionString)
 		/// </summary>
 		public int LibVersionNumber => GetConnection ().LibVersionNumber;
 
+		/// <summary>
+		/// The format to use when storing DateTime properties as strings. Ignored if StoreDateTimeAsTicks is true.
+		/// </summary>
+		/// <value>The date time string format.</value>
+		public string DateTimeStringFormat => GetConnection ().DateTimeStringFormat;
+
 		/// <summary>
 		/// The amount of time to wait for a table to become unlocked.
 		/// </summary>