Use Servlet API 3.0 for gitiles-dev

Gitiles is designed to compile and run against Servlet API 2.5, and
in particular the test classes FakeHttpServlet{Request,Response}
implement this API. To ensure compatibility in most of the code,
depend on 2.5 in the gerrit-servlet.

However, in gitiles-dev, we depend on Jetty 8, which requires Servlet
API 3.0. Use a different version from gitiles-servlet just for this
module. The combination of 2.5 for most code and 3.0 for dev also
helps check that Gitiles remains compatible with both Servlet API
versions.

Move the Jetty dependency out of the top-level pom.xml, since it's
only used by gitiles-dev. Switch to Servlet API jars provided by
Jetty, since we use Jetty elsewhere.

Change-Id: Ie4965574620441ed26e2986501d2c8949f451af6

gitiles-dev/pom.xml

diff --git a/gitiles-dev/pom.xml b/gitiles-dev/pom.xml
index 9a447f7..e89732a 100644
--- a/gitiles-dev/pom.xml
+++ b/gitiles-dev/pom.xml
@@ -32,6 +32,10 @@
     Gitiles running with an embedded Jetty server.
   </description>
 
+  <properties>
+    <jettyVersion>8.1.7.v20120910</jettyVersion>
+  </properties>
+
   <dependencies>
     <dependency>
       <groupId>com.google.gitiles</groupId>
@@ -40,9 +44,13 @@
     </dependency>
 
     <dependency>
-      <groupId>org.apache.tomcat</groupId>
-      <artifactId>servlet-api</artifactId>
-      <scope>provided</scope>
+      <groupId>org.eclipse.jetty.orbit</groupId>
+      <artifactId>javax.servlet</artifactId>
+      <!-- The bulk of Gitiles is designed to compile and run against Servlet API
+        2.5, but the embedded Jetty 8 in this module only requires Servlet API
+        3.0. -->
+      <version>3.0.0.v201112011016</version>
+      <scope>compile</scope>
     </dependency>
 
     <dependency>
@@ -52,6 +60,12 @@
     </dependency>
 
     <dependency>
+      <groupId>org.eclipse.jetty</groupId>
+      <artifactId>jetty-server</artifactId>
+      <version>${jettyVersion}</version>
+    </dependency>
+
+    <dependency>
       <groupId>org.slf4j</groupId>
       <artifactId>slf4j-simple</artifactId>
       <version>${slf4jVersion}</version>