Import wizard not compatible with Tycho/ManifestFirst

Created originally on Bitbucket by rickard (Rickard)

The import project wizard has a project detection wizard that stops traversing subdirectories when it encounters a POM file. In a Tycho/ManifestFirst layout, it is common to check in the .project files (since Tycho will generate the Maven metadata from OSGI metadata, not the other way around).

In addition, the Tycho pomgenerator will generate a parent POM for a project structure involving multiple bundles. If these bundles reside in the same HG repo, the import will detect the parent POM (which is not an Eclipse project at all), and stop traversing the subdirectories.