New: mk3d file format (#2795)

Fixes #1324

src/NzbDrone.Core.Test/ParserTests/QualityParserFixture.cs

@@ -323,6 +323,7 @@ namespace NzbDrone.Core.Test.ParserTests
         }
 
         [TestCase("Revolution.S01E02.Chained.Heat.mkv")]
+        [TestCase("Star.Wars.Episode.VII.The.Force.Awakens.mk3d")]
         [TestCase("Dexter - S01E01 - Title.avi")]
         [TestCase("the_x-files.9x18.sunshine_days.avi")]
         [TestCase("[CR] Sailor Moon - 004 [48CE2D0F].avi")]

src/NzbDrone.Core/MediaFiles/MediaFileExtensions.cs

@@ -66,6 +66,7 @@ namespace NzbDrone.Core.MediaFiles
 
                 //HD
                 { ".mkv", Source.WEBDL },
+                { ".mk3d", Source.WEBDL},
                 { ".ts", Source.TV },
                 { ".wtv", Source.TV },
 
@@ -77,6 +78,7 @@ namespace NzbDrone.Core.MediaFiles
             {
                 //HD
                 { ".mkv", Resolution.R720P },
+                { ".mk3d", Resolution.R720P },
                 { ".ts", Resolution.R720P },
                 { ".wtv", Resolution.R720P },