Increase the I/O buffer size to 81920 bytes

This significantly reduces the number of read and write calls when
reading large files.
81920 is the largest multiple of 4096 that is under the large object
heap limit (85,000 bytes).

RawFileType.cs

@@ -24,8 +24,6 @@ public sealed class RawFileType : FileType
         private static readonly string ExecutablePath = Path.Combine(Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location), "dcraw_emu.exe");
         private static readonly string OptionsFilePath = Path.Combine(Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location), "RawFileTypeOptions.txt");
 
-        private const int BufferSize = 4096;
-
         public RawFileType() : base(
             "RAW File",
             FileTypeFlags.SupportsLoading,
@@ -118,10 +116,12 @@ protected override Document OnLoad(Stream input)
             try
             {
                 // Write the input stream to a temporary file for LibRaw to load.
-                using (FileStream output = new FileStream(tempFile, FileMode.Create, FileAccess.Write, FileShare.None, BufferSize))
+                using (FileStream output = new FileStream(tempFile, FileMode.Create, FileAccess.Write, FileShare.None))
                 {
                     output.SetLength(input.Length);
-                    byte[] buffer = new byte[BufferSize];
+
+                    // 81920 is the largest multiple of 4096 that is under the large object heap limit (85,000 bytes).
+                    byte[] buffer = new byte[81920];
 
                     int bytesRead;
                     while ((bytesRead = input.Read(buffer, 0, buffer.Length)) > 0)