Supplement to Issue 143046: Feature/JS System Rework

Changes to support caching for the dual use of FeatureRegistry, and private to protected method changes for Guicing.

The delta's from the original issue:
java\gadgets\src\main\java\org\apache\shindig\gadgets\features\FeatureRegistry.java
66c66,67
<   private final Map<Collection<String>, List<FeatureResource>> cache = new MapMaker().makeMap();
---
>   private final Map<Collection<String>, List<FeatureResource>> cacheIgnoreUnsupported = new MapMaker().makeMap();
>   private final Map<Collection<String>, List<FeatureResource>> cacheOnlySupported = new MapMaker().makeMap();
180a182,183
>     Map<Collection<String>, List<FeatureResource>> cache = unsupported == null ? cacheIgnoreUnsupported
>     		 : cacheOnlySupported; 
225c228
<   public List<String> getFeatures(List<String> needed) {
---
>   public List<String> getFeatures(Collection<String> needed) {

java\gadgets\src\main\java\org\apache\shindig\gadgets\render\RenderingGadgetRewriter.java
87c87
<   static final String DEFAULT_CSS =
---
>   static protected final String DEFAULT_CSS =
92,93c92,93
<   static final String INSERT_BASE_ELEMENT_KEY = "gadgets.insertBaseElement";
<   static final String FEATURES_KEY = "gadgets.features";
---
>   static protected final String INSERT_BASE_ELEMENT_KEY = "gadgets.insertBaseElement";
>   static protected final String FEATURES_KEY = "gadgets.features";
95,100c95,100
<   private final MessageBundleFactory messageBundleFactory;
<   private final ContainerConfig containerConfig;
<   private final FeatureRegistry featureRegistry;
<   private final UrlGenerator urlGenerator;
<   private final RpcServiceLookup rpcServiceLookup;
<   private Set<String> defaultExternLibs = ImmutableSet.of();
---
>   protected final MessageBundleFactory messageBundleFactory;
>   protected final ContainerConfig containerConfig;
>   protected final FeatureRegistry featureRegistry;
>   protected final UrlGenerator urlGenerator;
>   protected final RpcServiceLookup rpcServiceLookup;
>   protected Set<String> defaultExternLibs = ImmutableSet.of();
330c330
<   private String getLibraryConfig(Gadget gadget, List<String> reqs)
---
>   protected String getLibraryConfig(Gadget gadget, List<String> reqs)