Further work on making JMustache work in GWT.

I've ironed out most of the kinks, but the GWT unit test still fails because
we're forced to do some sneaky things with java.io.Reader/Writer. I think it
will all work when compiled to JavaScript, so I need to check it in a real
project.

src/test/java/com/samskivert/mustache/GwtTestMustache.java

@@ -0,0 +1,43 @@
+//
+// JMustache - A Java implementation of the Mustache templating language
+// http://github.com/samskivert/jmustache/blob/master/LICENSE
+
+package com.samskivert.mustache;
+
+import java.util.HashMap;
+import java.util.Map;
+
+import com.google.gwt.junit.client.GWTTestCase;
+
+import org.junit.*;
+import static org.junit.Assert.*;
+
+/**
+ * Tests basic Mustache operation in GWT.
+ */
+public class GwtTestMustache extends GWTTestCase
+{
+    public String getModuleName () {
+        return "com.samskivert.Mustache";
+    }
+
+    @Test public void testSimpleVariable () {
+        test("bar", "{{foo}}", context("foo", "bar"));
+    }
+
+    protected void test (String expected, String template, Object ctx) {
+        test(Mustache.compiler(), expected, template, ctx);
+    }
+
+    protected void test (Mustache.Compiler compiler, String expected, String template, Object ctx) {
+        assertEquals(expected, compiler.compile(template).execute(ctx));
+    }
+
+    protected Object context (Object... data) {
+        Map<String, Object> ctx = new HashMap<String, Object>();
+        for (int ii = 0; ii < data.length; ii += 2) {
+            ctx.put(data[ii].toString(), data[ii+1]);
+        }
+        return ctx;
+    }
+}