KS Compiler generates GO files with non standard header  
GO files generated by the KS Compiler do not respect the [standard header for generated GO files](https://golang.org/cmd/go/#hdr-Generate_Go_files_by_processing_source).

The header should match the pattern `^// Code generated .* DO NOT EDIT\.$`, thus the header could be something like:

```go
// Code generated by kaitai-struct-compiler from a .ksy source file. DO NOT EDIT.
```

This (minor) bug can be fixed by adding the following line at the beginning of the `GoCompiler` class

```scala
override val headerComment = "Code generated by kaitai-struct-compiler from a .ksy source file. DO NOT EDIT."
```