Enabled more tests, fixed more bugs.

Mainly we also needed to trim around comment tags, but also there were a bunch
of tricky edge cases that were only partially addressed. This is some edgy
business!

src/test/java/com/samskivert/mustache/specs/SpecRunner.java

@@ -47,7 +47,7 @@ public class SpecRunner extends BlockJUnit4ClassRunner
 
     private List<FrameworkMethod> computeTests () throws InitializationError {
         String[] groups =  new String[] {
-            // "comments",
+            "comments",
             "delimiters",
             "interpolation",
             "inverted",