observatory herald (#30)

* WIP: initial commit for observatory herald

* Plugin error handling refactor

* make error window non-modal

* tidy up plugin error handling

* first pass for basic herald functionality

* corrections for linux env

* Use FNV hash directly instead of managing through dictionary/index file

* resolve audio queuing issue, switch to personal NetCoreAudio fork

* merge cleanup

* add enable setting, populate defaults

* framework xml doc update

* Adjust settings, add style selection, replace locale with demonym in dropdown list.

* Test is position is on screen before saving/loading.

* use a default that's actually in the list

ObservatoryCore/UI/ViewModels/MainWindowViewModel.cs

@@ -1,6 +1,6 @@
 using System;
 using System.Collections.Generic;
-using System.Text;
+using System.Linq;
 
 namespace Observatory.UI.ViewModels
 {
@@ -9,6 +9,9 @@ namespace Observatory.UI.ViewModels
         public MainWindowViewModel(PluginManagement.PluginManager pluginManager)
         {
             core = new CoreViewModel(pluginManager.workerPlugins, pluginManager.notifyPlugins);
+
+            if (pluginManager.errorList.Any())
+                ErrorReporter.ShowErrorPopup("Plugin Load Error", string.Join(Environment.NewLine, pluginManager.errorList));
         }
 
         public CoreViewModel core { get; }