UseJava: add INCLUDE_MODULES argument to add_jar

Arguments are added to the dependencies list, and to the "--module-path"
passed to javac, which is only generated for adequate JDK versions.

Tests/JavaModExportImport/BuildExport/Foo.java

@@ -0,0 +1,13 @@
+package org.foo;
+
+public class Foo
+{
+  public Foo()
+  {
+  }
+
+  public void printName()
+  {
+    System.out.println("Foo");
+  }
+}