Updated clean to only clean measurement files

Author: sksamuel

src/main/scala/scoverage/IOUtils.scala

@@ -13,7 +13,7 @@ object IOUtils {
   private val CoverageFileName = "scoverage.coverage.xml"
   val DataDir = "scoverage-data"
 
-  def clean(dataDir: File): Unit = dataDir.listFiles.foreach(_.delete())
+  def clean(dataDir: File): Unit = findMeasurementFiles(dataDir).foreach(_.delete)
   def clean(dataDir: String): Unit = clean(new File(dataDir))
 
   def coverageFile(dataDir: File): File = coverageFile(dataDir.getAbsolutePath)

src/main/scala/scoverage/plugin.scala

@@ -101,7 +101,7 @@ class ScoverageInstrumentationComponent(val global: Global)
   def setOptions(options: ScoverageOptions): Unit = {
     this.options = options
     coverageFilter = new RegexCoverageFilter(options.excludedPackages)
-    new File(options.dataDir).mkdirs()
+    new File(options.dataDir).mkdirs() // ensure data directory is created
   }
 
   override def newPhase(prev: scala.tools.nsc.Phase): Phase = new Phase(prev) {