Updated Version to support comparisons

src/main/scala/com/sothr/imagetools/util/Version.scala

@@ -8,14 +8,60 @@ class Version(val versionString:String) {
   val (major,minor,revision,buildType) = {
     val splitVersion = versionString.split("""\.""")
     val splitType = splitVersion(splitVersion.length-1).split("""-""")
-    (splitVersion(0),splitVersion(1),splitType(0),splitType(1))
+    (splitVersion(0).toInt,splitVersion(1).toInt,splitType(0).toInt,splitType(1))
   }
 
-  def difference(otherVersion:Version):Integer = {
-    return -1
+  /*
+  * -3 = this.revision < that.revision
+  * -2 = this.minor < that.minor
+  * -1 = this.major < that.major
+  * 0 = Identical Versions
+  * 1 = this.major > that.major
+  * 2 = this.minor > that.minor
+  * 3 = this.revision > that.revision
+  * 4 = this.buildType != that.buildType
+  */
+  def difference(that:Version):Integer = {
+    if (this.hashCode == that.hashCode) return 0
+    if (this.major > that.major) {
+      return 1
+    } else if (this.major < that.major){
+      return -1
+    //major is the same
+    } else {
+      if (this.minor > that.minor) {
+        return 2
+      } else if (this.minor < that.minor) {
+        return -2
+      //major.minor are the same
+      } else {
+        if (this.revision > that.revision) {
+          return 3
+        } else if (this.revision < that.revision) {
+          return -3
+        //major.minor.revision are all the same
+        } else {
+          if (this.buildType != that.buildType) {
+            return 4
+          }
+          //should be caught by the first if, but incase not
+          return 0
+        }
+      }
+    }
   }
 
   override def toString():String = {
     return s"$major.$minor.$revision-$buildType"
   }
+  
+  override def hashCode(): Int = {
+    val prime:Int = 37;
+    val result:Int = 255
+    var hash:Int = major
+    hash += minor
+    hash += revision
+    hash += buildType.hashCode
+    return prime * result + hash
+  }
 }