Remove progress dialogs for xliff initialization

[StephenMcConnel]

This was discussed at the conference. I think this is the minimal change to the code that allows current behavior for programs that may still benefit from it.

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This change is 

[tombogle]

src/L10NSharp/XLiffUtils/XLiffLocalizationManager.cs line 209 at r3 (raw file):

          var stringCache = new XLiffLocalizedStringCache(this, false);

          var extractedInfo = ExtractStringsWIthoutDialog(Name, additionalLocalizationMethods, namespaceBeginnings);

Not sure if "WithoutDialog" is particularly meaningful if there is NEVER a dialog.