Support for dependency domains of package.xml

[hwiedPro]

Hi, thanks for autoproj.

This is a feature request.
Autoproj supports package.xml parsing for dependency resolution. package.xml defines dependencies according to their domain:

• depend
• build_depend
• build_export_depend
• buildtool_depend
• exec_depend
• test_depend
• doc_depend

It would be good if autoproj categorizes the dependency, so that it would be possible to at least have an (e.g.) autoproj osdeps --domain <build|exec|...> option to install those deps. And also a functionality to print those deps in a parseable format.

Thanks already in advance!