Make @ProvidedBy take a javax.inject.Provider.

Fixes google/guice#808.

core/src/com/google/inject/ProvidedBy.java

@@ -34,5 +34,5 @@
   /**
    * The implementation type.
    */
-  Class<? extends Provider<?>> value();
+  Class<? extends javax.inject.Provider<?>> value();
 }

core/src/com/google/inject/internal/Errors.java

@@ -201,7 +201,7 @@ public Errors bindingToProvider() {
     return addMessage("Binding to Provider is not allowed.");
   }
 
-  public Errors subtypeNotProvided(Class<? extends Provider<?>> providerType,
+  public Errors subtypeNotProvided(Class<? extends javax.inject.Provider<?>> providerType,
       Class<?> type) {
     return addMessage("%s doesn't provide instances of %s.", providerType, type);
   }

core/src/com/google/inject/internal/InjectorImpl.java

@@ -699,7 +699,7 @@ private <T> BindingImpl<TypeLiteral<T>> createTypeLiteralBinding(
   <T> BindingImpl<T> createProvidedByBinding(Key<T> key, Scoping scoping,
       ProvidedBy providedBy, Errors errors) throws ErrorsException {
     Class<?> rawType = key.getTypeLiteral().getRawType();
-    Class<? extends Provider<?>> providerType = providedBy.value();
+    Class<? extends javax.inject.Provider<?>> providerType = providedBy.value();
 
     // Make sure it's not the same type. TODO: Can we check for deeper loops?
     if (providerType == rawType) {

core/src/com/google/inject/internal/ProvidedByInternalFactory.java

@@ -21,10 +21,11 @@
 
 import com.google.inject.Key;
 import com.google.inject.ProvidedBy;
-import com.google.inject.Provider;
 import com.google.inject.internal.InjectorImpl.JitLimitation;
 import com.google.inject.spi.Dependency;
 
+import javax.inject.Provider;
+
 /**
  * An {@link InternalFactory} for {@literal @}{@link ProvidedBy} bindings.
  *