Install files from group before executing Rules

I build some module like the `Exporter.qbs` but for copying header. I create some "pretty" header for every type just including the original header (like Qt itself does). The problem is that when using with
```
Group

{ fileTagsFilter: [ "Exporter.cppHeader.public", "Exporter.cppHeader.pretty" ] qbs.installDir: "include" }

Group

{ fileTagsFilter: [ "Exporter.cppHeader.private" ] qbs.installDir: "include/private" }

```
the product compiles while copying the files. Since the library, which headers, are to be exported, itself uses the include directory the the first compile run exits with an error.
So if files from groups are installed before executing rules the problem would not exists (and an "Exporter.cppHeader" could be created which works the same way "Exporter.qbs" works).