Certificate/wireless plugins; major refactoring

Migrate much of BI to Services.
Added Wireless Profile Provider plugin feature.
Added Certificate Authority Provider plugin feature.
Modified Certificate Provider plugin feature.
Database migration v17, for Device Profiles.
Enrolment Client Updated to support CA Certificates, Wireless Profiles
and Hardware Info.
New Client Enrolment Protocol to support new features.
Plugin Manifest Generator added to main solution.
Improved AD search performance.

Disco.Services/Documents/AttachmentImport/ThumbnailUpdateTask.cs

@@ -0,0 +1,128 @@
+using Disco.Data.Repository;
+using Disco.Models.Repository;
+using Disco.Services.Tasks;
+using Quartz;
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Threading;
+
+namespace Disco.Services.Documents.AttachmentImport
+{
+    public class ThumbnailUpdateTask : ScheduledTask
+    {
+        public override string TaskName { get { return "Migration: PDF Attachment Thumbnail Update"; } }
+
+        public override bool SingleInstanceTask { get { return true; } }
+        public override bool CancelInitiallySupported { get { return false; } }
+
+        #region Required Helpers
+        private static string RequiredFilePath(DiscoDataContext Database)
+        {
+            if (Database.DiscoConfiguration.DataStoreLocation != null)
+                return Path.Combine(Database.DiscoConfiguration.DataStoreLocation, "_ThumbnailUpdateRequired.txt");
+            else
+                return null;
+        }
+
+        public static bool IsRequired(DiscoDataContext Database)
+        {
+            var requiredFilePath = RequiredFilePath(Database);
+
+            if (requiredFilePath == null)
+                return false;
+            else
+                return File.Exists(requiredFilePath);
+        }
+        public static void SetRequired(DiscoDataContext Database)
+        {
+            var requiredFilePath = RequiredFilePath(Database);
+
+            if (requiredFilePath != null)
+            {
+                File.WriteAllText(requiredFilePath, "This file exists to indicate a Thumbnail Update is required. It will automatically be deleted when the update completes.");
+                File.SetAttributes(requiredFilePath, FileAttributes.Hidden);
+            }
+        }
+        #endregion
+
+        public override void InitalizeScheduledTask(DiscoDataContext Database)
+        {
+            if (IsRequired(Database))
+            {
+                // Schedule in 5mins
+                var trigger = TriggerBuilder.Create()
+                    .StartAt(DateTimeOffset.Now.AddMinutes(5));
+
+                this.ScheduleTask(trigger);
+            }
+        }
+
+        public static ScheduledTaskStatus ScheduleImmediately()
+        {
+            var existingTask = ScheduledTasks.GetTaskStatuses(typeof(ThumbnailUpdateTask)).Where(s => s.IsRunning).FirstOrDefault();
+            if (existingTask != null)
+                return existingTask;
+
+            var instance = new ThumbnailUpdateTask();
+            return instance.ScheduleTask();
+        }
+
+        protected override void ExecuteTask()
+        {
+            using (DiscoDataContext database = new DiscoDataContext())
+            {
+                Status.UpdateStatus(0, "Updating Attachment PDF Thumbnails", "Reading Attachments");
+
+                // Attachments
+                List<IAttachment> attachments = database
+                    .DeviceAttachments.Where(da => da.MimeType == "application/pdf").ToList().Cast<IAttachment>()
+                    .Concat(database.UserAttachments.Where(da => da.MimeType == "application/pdf").ToList().Cast<IAttachment>())
+                    .Concat(database.JobAttachments.Where(da => da.MimeType == "application/pdf").ToList().Cast<IAttachment>())
+                    .ToList();
+
+                int failedTotal = 0;
+                int notFoundTotal = 0;
+                int completedTotal = 0;
+
+                attachments.AsParallel().ForAll(a =>
+                {
+                    var completed = Interlocked.Increment(ref completedTotal);
+                    if ((completed % 10) == 0)
+                    {
+                        Status.UpdateStatus((100D / attachments.Count) * completed, $"Processing: {a.AttachmentType} Attachment, Id: {a.Id}");
+                    }
+                    try
+                    {
+                        var fileName = a.RepositoryFilename(database);
+                        if (!File.Exists(fileName))
+                        {
+                            Interlocked.Increment(ref notFoundTotal);
+                            Status.LogWarning($"Attachment not found in the Data Store. [{a.AttachmentType} Attachment, Id {a.Id}] expected at: '{fileName}'");
+                        }
+                        else
+                        {
+                            a.GenerateThumbnail(database);
+                        }
+                    }
+                    catch (Exception ex)
+                    {
+                        Interlocked.Increment(ref failedTotal);
+                        Status.LogWarning($"Error when generating thumbnail for [{a.AttachmentType} Attachment, Id {a.Id}]: [{ex.GetType().Name}] {ex.Message}");
+                    }
+                });
+
+                // Finished - Remove Placeholder File
+                var requiredFilePath = RequiredFilePath(database);
+                if (requiredFilePath != null && File.Exists(requiredFilePath))
+                    File.Delete(requiredFilePath);
+
+                Status.SetFinishedMessage($"Finished updating thumbnails for {attachments.Count:N0}. {notFoundTotal:N0} were not found. {failedTotal:N0} failed.");
+                Status.LogInformation(Status.FinishedMessage);
+                Status.Finished();
+            }
+        }
+
+    }
+}