Project's flavour should automatically detected, instead of being hardcoded in the settings

Currently, the default sbteclipse flavour for a project is ScalaIDE (see here), and I don't see why that should be the case.

Ideally, the project's flavour should be automatically detected based on the fact that the scala-library JAR is in the classpath. This is useful if you are trying to import a pure Java project, with no dependency on the Scala library. This doesn't currently work because the generated .project include the Scala builder and Scala nature (this is because ScalaIDE flavour is selected), but since there is no Scala library in the .classpath, you will get an error once the project is opened in Eclipse.

The actual reason why I would like to have it working this way is because I want sbteclipse to generate the Eclipse files for importing the playframework codebase.

Start in src/main/scala/com/typesafe/sbteclipse/core/EclipsePlugin.scala at the default flavour setting referenced in the issue, then inspect how the generated .project and .classpath are assembled. Determine how the scala-library JAR is represented in the classpath and verify that a pure Java project no longer receives the Scala builder or Scala nature, while Scala projects retain them.