Fix assembly only working on UNIX-like machines

The path matching will now be independent of the actual representation
of a path on the user's platform.

build.sbt

@@ -27,8 +27,10 @@ lazy val generator = (project in file("."))
       case "MANIFEST.MF" => MergeStrategy.first
       case "plugin.xml" => MergeStrategy.discard
       case "plugin.properties" => MergeStrategy.discard
-      case "schema/generated_package.exsd" => MergeStrategy.discard
-      case "schema/dynamic_package.exsd" => MergeStrategy.discard
+      case "generated_package.exsd" => MergeStrategy.discard
+      case "dynamic_package.exsd" => MergeStrategy.discard
+      case PathList("schema", ps @ _ *) if ps.lastOption.exists(_.endsWith("generated_package.exsd")) => MergeStrategy.discard
+      case PathList("schema", ps @ _ *) if ps.lastOption.exists(_.endsWith("dynamic_package.exsd")) => MergeStrategy.discard
       case x =>
         val oldStrategy = (assemblyMergeStrategy in assembly).value
         oldStrategy(x)