Use Manifest version at runtime to reduce duplication

This use of "in Global" for build.sbt is not ideal,
but I don't understand SBT enough to know why I need it.

Author: Charles O'Farrell

Scalatron/src/scalatron/Version.scala

@@ -5,5 +5,5 @@ package scalatron
 
 object Version
 {
-    val VersionString = "0.9.9.1"
+    val VersionString = Version.getClass.getPackage.getImplementationVersion
 }

ScalatronCLI/src/scalatronRemote/Version.scala

@@ -4,5 +4,5 @@
 package scalatronRemote
 
 object Version {
-    val VersionString = "0.9.9.1" // version of this tool (not of remote server :-)
+    val VersionString = Version.getClass.getPackage.getImplementationVersion // version of this tool (not of remote server :-)
 }

build.sbt

@@ -2,6 +2,6 @@ organization := "Scalatron"
 
 name         := "Scalatron"
 
-version      := "0.9.9.1"
+version in Global := "0.9.9.1"
 
 scalaVersion := "2.9.1"

project/build.scala

@@ -7,6 +7,14 @@ import AssemblyKeys._
 object build extends Build {
     def standardSettings = Defaults.defaultSettings ++ src ++ assemblySettings ++ Seq (
         mergeStrategy in assembly := {_ => MergeStrategy.first}
+    ) ++ implVersion
+
+    lazy val implVersion = Seq (
+        packageOptions <<= (version) map {
+            scalatronVersion => Seq(Package.ManifestAttributes(
+                ("Implementation-Version", scalatronVersion)
+            ))
+        }
     )
 
     lazy val all = Project(