Addressing https://github.com/harrah/xsbt/pull/418

Changed the order of parameters in getScala method.
Changed the key name to scalaOrganization (scala-organization).
Augmented description of the key.
Minor fixes.

launch/Launch.scala

@@ -84,10 +84,12 @@ class Launch private[xsbt](val bootDirectory: File, val lockBoot: Boolean, val i
 	bootDirectory.mkdirs
 	private val scalaProviders = new Cache[(String, String), String, xsbti.ScalaProvider]((x, y) => getScalaProvider(x._1, x._2, y))
 	def getScala(version: String): xsbti.ScalaProvider = getScala(version, "")
-	def getScala(version: String, reason: String): xsbti.ScalaProvider = getScala(BootConfiguration.ScalaOrg, version, reason)
-	def getScala(scalaOrg: String, version: String, reason: String) = scalaProviders((scalaOrg, version), reason)
+	def getScala(version: String, reason: String): xsbti.ScalaProvider = getScala(version, reason, BootConfiguration.ScalaOrg)
+	def getScala(version: String, reason: String, scalaOrg: String) = scalaProviders((scalaOrg, version), reason)
 	def app(id: xsbti.ApplicationID, version: String): xsbti.AppProvider = app(id, Option(version))
-    def app(id: xsbti.ApplicationID, scalaVersion: Option[String]): xsbti.AppProvider = getAppProvider(id, scalaVersion, false)
+    def app(id: xsbti.ApplicationID, scalaVersion: Option[String]): xsbti.AppProvider = 
+      getAppProvider(id, scalaVersion, false)
+
 	val bootLoader = new BootFilteredLoader(getClass.getClassLoader)
 	val topLoader = jnaLoader(bootLoader)
 

launch/interface/src/main/java/xsbti/Launcher.java

@@ -7,7 +7,7 @@ public interface Launcher
 	public static final int InterfaceVersion = 1;
 	public ScalaProvider getScala(String version);
 	public ScalaProvider getScala(String version, String reason);
-	public ScalaProvider getScala(String scalaOrg, String version, String reason);
+	public ScalaProvider getScala(String version, String reason, String scalaOrg);
 	public AppProvider app(ApplicationID id, String version);
 	public ClassLoader topLoader();
 	public GlobalLock globalLock();

main/Defaults.scala

@@ -52,7 +52,7 @@ object Defaults extends BuildCommon
 	))
 	def globalCore: Seq[Setting[_]] = inScope(GlobalScope)(defaultTestTasks(test) ++ defaultTestTasks(testOnly) ++ defaultTestTasks(testQuick) ++ Seq(
 		crossVersion :== CrossVersion.Disabled,
-		scalaOrg :== "org.scala-lang",
+		scalaOrganization :== ScalaArtifacts.Organization,
 		buildDependencies <<= buildDependencies or Classpaths.constructBuildDependencies,
 		taskTemporaryDirectory := IO.createTemporaryDirectory,
 		onComplete <<= taskTemporaryDirectory { dir => () => IO.delete(dir); IO.createDirectory(dir) },
@@ -265,10 +265,10 @@ object Defaults extends BuildCommon
 			}
 		}
 	}
-	def scalaInstanceSetting = (appConfiguration, scalaOrg, scalaVersion, scalaHome) map { (app, scalaOrg, version, home) =>
+	def scalaInstanceSetting = (appConfiguration, scalaOrganization, scalaVersion, scalaHome) map { (app, org, version, home) =>
 		val launcher = app.provider.scalaProvider.launcher
 		home match {
-			case None => ScalaInstance(scalaOrg, version, launcher)
+			case None => ScalaInstance(org, version, launcher)
 			case Some(h) => ScalaInstance(h, launcher)
 		}
 	}

main/Keys.scala

@@ -135,7 +135,7 @@ object Keys
 	val compileInputs = TaskKey[Compiler.Inputs]("compile-inputs", "Collects all inputs needed for compilation.", DTask)
 	val scalaHome = SettingKey[Option[File]]("scala-home", "If Some, defines the local Scala installation to use for compilation, running, and testing.", ASetting)
 	val scalaInstance = TaskKey[ScalaInstance]("scala-instance", "Defines the Scala instance to use for compilation, running, and testing.", DTask)
-	val scalaOrg = SettingKey[String]("scala-org", "Artifact id of Scala scala used in the project.", CSetting)
+	val scalaOrganization = SettingKey[String]("scala-organization", "Organization/group ID of the Scala used in the project. Default value is 'org.scala-lang'.", CSetting)
 	val scalaVersion = SettingKey[String]("scala-version", "The version of Scala used for building.", APlusSetting)
 	val scalaBinaryVersion = SettingKey[String]("scala-binary-version", "The Scala version substring describing binary compatibility.", BPlusSetting)
 	val crossScalaVersions = SettingKey[Seq[String]]("cross-scala-versions", "The versions of Scala used when cross-building.", BPlusSetting)

util/classpath/ScalaInstance.scala

@@ -24,7 +24,7 @@ object ScalaInstance
 	val VersionPrefix = "version "
 	
 	def apply(org: String, version: String, launcher: xsbti.Launcher): ScalaInstance =
-		apply(version, launcher.getScala(org, version, ""))
+		apply(version, launcher.getScala(version, "", org))
 	/** Creates a ScalaInstance using the given provider to obtain the jars and loader.*/
 	def apply(version: String, launcher: xsbti.Launcher): ScalaInstance =
 		apply(version, launcher.getScala(version))