Use enum as flag correctly

Check PreserveFileTime when file times are initialized.

SharpCompress/Archive/IArchiveEntry.Extensions.cs

@@ -90,7 +90,7 @@ namespace SharpCompress.Archive
                 FileInfo nf = new FileInfo(destinationFileName);
                 if (nf.Exists)
                 {
-                    if (options.HasFlag(ExtractOptions.PreserveAttributes))
+                    if (options.HasFlag(ExtractOptions.PreserveFileTime))
                     {
                         if (entry.CreatedTime.HasValue)
                         {

SharpCompress/Common/ExtractOptions.cs

@@ -5,26 +5,26 @@ namespace SharpCompress.Common
     [Flags]
     public enum ExtractOptions
     {
-        None,
+        None = 0,
 
         /// <summary>
         /// overwrite target if it exists
         /// </summary>
-        Overwrite,
+        Overwrite = 1 << 0,
 
         /// <summary>
         /// extract with internal directory structure
         /// </summary>
-        ExtractFullPath,
+        ExtractFullPath = 1 << 1,
 
         /// <summary>
         /// preserve file time
         /// </summary>
-        PreserveFileTime,
+        PreserveFileTime = 1 << 2,
 
         /// <summary>
         /// preserve windows file attributes
         /// </summary>
-        PreserveAttributes,
+        PreserveAttributes = 1 << 3,
     }
 }