Fixed sbt, sbt-eclipse and managed source directory.

build.sbt

@@ -22,10 +22,4 @@ antlr4GenListener in Antlr4 := false
 
 antlr4GenVisitor in Antlr4 := false
 
-sourceManaged := file("target/gen")
-
-unmanagedSourceDirectories in Compile <++= baseDirectory { base =>
-  Seq(
-    base / "target/gen/main"
-  )
-}
+EclipseKeys.createSrc := EclipseCreateSrc.Default + EclipseCreateSrc.Resource + EclipseCreateSrc.Managed
\ No newline at end of file

project/sbt-eclipse.sbt

+addSbtPlugin("com.typesafe.sbteclipse" % "sbteclipse-plugin" % "2.5.0")