Bump protobuf dependency up to 2.5.0.

Author: Sheridan C Rawlins

pom.xml

@@ -42,7 +42,7 @@
 		<dependency>
 			<groupId>com.google.protobuf</groupId>
 			<artifactId>protobuf-java</artifactId>
-			<version>2.4.1</version>
+			<version>2.5.0</version>
 			<scope>provided</scope>
 		</dependency>
 		<dependency>

src/test/resources/proto/unittest.proto

@@ -410,6 +410,7 @@ message TestNestedMessageHasBits {
 
 // Test an enum that has multiple values with the same number.
 enum TestEnumWithDupValue {
+  option allow_alias=true;
   FOO1 = 1;
   BAR1 = 2;
   BAZ = 3;