Wrap the stock Jython JSR-223 ScriptEngine

We wanted to do this before, but 2.5.3 has a bug which did not occur
with the SciJava ScriptEngine implementation, so we stuck with that.

But now that we switched to Jython 2.7.0, it is no longer an issue.

Author: ctrueden

src/main/java/org/scijava/plugins/scripting/jython/JythonScriptLanguage.java

@@ -62,15 +62,6 @@ public JythonScriptLanguage() {
 		super("jython");
 	}
 
-	@Override
-	public ScriptEngine getScriptEngine() {
-		// NB: recursive priorities can only be resolved via inter-service
-		// dependencies. There is no way to make the ScriptService
-		// depend on the JythonService because of the hierarchy
-		// of components. So we have to get the JythonService indirectly.
-		return context.service(JythonService.class).getScriptEngine();
-	}
-
 	@Override
 	public Object decode(final Object object) {
 		if (object instanceof PyNone) return null;

src/test/java/org/scijava/plugins/scripting/jython/JythonTest.java

@@ -46,6 +46,7 @@
 import org.junit.After;
 import org.junit.Before;
 import org.junit.Test;
+import org.python.jsr223.PyScriptEngine;
 import org.scijava.Context;
 import org.scijava.script.ScriptLanguage;
 import org.scijava.script.ScriptModule;
@@ -87,7 +88,7 @@ public void testBasic() throws InterruptedException, ExecutionException,
 	public void testLocals() throws ScriptException {
 		final ScriptLanguage language = scriptService.getLanguageByExtension("py");
 		final ScriptEngine engine = language.getScriptEngine();
-		assertEquals(JythonScriptEngine.class, engine.getClass());
+		assertEquals(PyScriptEngine.class, engine.getClass());
 		engine.put("hello", 17);
 		assertEquals(17, language.decode(engine.eval("hello")));
 		assertEquals(17, language.decode(engine.get("hello")));
@@ -117,20 +118,20 @@ public void testParameters() throws InterruptedException, ExecutionException,
 	 * Tests that variables assigned a primitive long value have the expected
 	 * type.
 	 * <p>
-	 * There is a crazy bug in {@link org.python.jsr223.PyScriptEngine}, which
-	 * results in variables assigned a long primitive to somehow end up as (or
+	 * There was a crazy bug in {@link PyScriptEngine} version 2.5.3, which
+	 * resulted in variables assigned a long primitive to somehow end up as (or
 	 * appearing to end up as) {@link java.math.BigInteger} instances instead. See
 	 * <a href=
 	 * "http://sourceforge.net/p/jython/mailman/jython-users/thread/54370FE9.5010603%40farowl.co.uk/"
 	 * >this thread on the jython-users mailing list</a> for discussion.
 	 * </p>
 	 * <p>
-	 * This test ensures that that specific problem gets flagged if it occurs. As
-	 * long as we keep using our own Jython {@code ScriptEngine} implementation
-	 * (i.e.: {@link org.scijava.plugins.scripting.jython.JythonScriptEngine}),
-	 * the problem does not occur. But if we switch to the stock JSR-223 Jython
-	 * {@code ScriptEngine} (i.e.: {@link org.python.jsr223.PyScriptEngine}), the
-	 * problem manifests. See {@link JythonScriptLanguage#getScriptEngine()}.
+	 * This test ensures that that specific problem gets flagged if it recurs.
+	 * Previously, to avoid it, we used our own Jython {@code ScriptEngine}
+	 * implementation
+	 * ({@code org.scijava.plugins.scripting.jython.JythonScriptEngine}). But
+	 * since Jython 2.7.0, the stock JSR-223 Jython {@code ScriptEngine} (i.e.:
+	 * {@link org.python.jsr223.PyScriptEngine}) no longer has this issue.
 	 * </p>
 	 */
 	@Test