[Symbian Installation File] Add skipped file entry type found in the wild.

Aaru.Archives/Symbian/Enums.cs

@@ -420,7 +420,11 @@ public sealed partial class Symbian
         If     = 3,
         ElseIf = 4,
         Else   = 5,
-        EndIf  = 6
+        EndIf  = 6,
+        /// <summary>
+        ///     Found in the wild, doesn't seem to contain any data, and doesn't count like a file entry either
+        /// </summary>
+        Skip = 0xFFFFFFFF
     }
 
 #endregion

Aaru.Archives/Symbian/Parser.cs

@@ -553,6 +553,11 @@ public sealed partial class Symbian
                 _conditions.Add(tabulation             + "endif()" + Environment.NewLine);
                 offset = (uint)(br.BaseStream.Position + Marshal.SizeOf<ConditionalEndRecord>());
 
+                break;
+            case FileRecordType.Skip:
+                offset = (uint)br.BaseStream.Seek(sizeof(FileRecordType), SeekOrigin.Current);
+                currentFile--;
+
                 break;
             default:
                 throw new ArgumentOutOfRangeException();