Add some new music-related person types and parse from ffprobe

MediaBrowser.Model/Entities/PersonType.cs

@@ -1,42 +1,42 @@
 namespace MediaBrowser.Model.Entities
 {
     /// <summary>
-    /// Struct PersonType.
+    /// Types of persons.
     /// </summary>
-    public class PersonType
+    public static class PersonType
     {
         /// <summary>
-        /// The actor.
+        /// A person whose profession is acting on the stage, in films, or on television.
         /// </summary>
         public const string Actor = "Actor";
 
         /// <summary>
-        /// The director.
+        /// A person who supervises the actors and other staff in a film, play, or similar production.
         /// </summary>
         public const string Director = "Director";
 
         /// <summary>
-        /// The composer.
+        /// A person who writes music, especially as a professional occupation.
         /// </summary>
         public const string Composer = "Composer";
 
         /// <summary>
-        /// The writer.
+        /// A writer of a book, article, or document. Can also be used as a generic term for music writer if there is a lack of specificity.
         /// </summary>
         public const string Writer = "Writer";
 
         /// <summary>
-        /// The guest star.
+        /// A well-known actor or other performer who appears in a work in which they do not have a regular role.
         /// </summary>
         public const string GuestStar = "GuestStar";
 
         /// <summary>
-        /// The producer.
+        /// A person responsible for the financial and managerial aspects of the making of a film or broadcast or for staging a play, opera, etc.
         /// </summary>
         public const string Producer = "Producer";
 
         /// <summary>
-        /// The conductor.
+        /// A person who directs the performance of an orchestra or choir.
         /// </summary>
         public const string Conductor = "Conductor";
 
@@ -44,5 +44,25 @@ namespace MediaBrowser.Model.Entities
         /// The lyricist.
         /// </summary>
         public const string Lyricist = "Lyricist";
+
+        /// <summary>
+        /// A person who writes the words to a song or musical.
+        /// </summary>
+        public const string Arranger = "Arranger";
+
+        /// <summary>
+        /// An audio engineer who performed a general engineering role.
+        /// </summary>
+        public const string Engineer = "Engineer";
+
+        /// <summary>
+        /// An engineer responsible for using a mixing console to mix a recorded track into a single piece of music suitable for release.
+        /// </summary>
+        public const string Mixer = "Mixer";
+
+        /// <summary>
+        /// A person who remixed a recording by taking one or more other tracks, substantially altering them and mixing them together with other material.
+        /// </summary>
+        public const string Remixer = "Remixer";
     }
 }