polish web.Mock* classpath

Previously when running the tests for spring-web, spring-webmvc,
spring-test-mvc, and spring-orm there were possible collissions in the
classpath due to the fact that each had its own copy of the web.Mock*
classes in it. This causes uncertainty for which class the code was
running against. Furthermore, the maintance of keeping the copies up to
date was tedious.

Now there are two copies of the web.Mock* classes. The ones that exist
in spring-test main sources and a copy that supports servlet 3 within
spring-web test sources. The copy in spring-web test sources has been
moved to a new package to avoid having the classes exist twice on the
classpath within Eclipse.

build.gradle

@@ -432,6 +432,7 @@ project('spring-orm') {
         testCompile "commons-dbcp:commons-dbcp:1.2.2"
         testCompile "org.eclipse.persistence:org.eclipse.persistence.asm:1.0.1"
         testCompile "org.eclipse.persistence:org.eclipse.persistence.antlr:1.0.1"
+        testCompile project(":spring-web").sourceSets.test.output
         compile project(":spring-core")
         compile project(":spring-beans")
         compile(project(":spring-aop"), optional)
@@ -502,6 +503,7 @@ project('spring-webmvc') {
             exclude group: 'xom', module: 'xom'
             exclude group: 'xerces', module: 'xercesImpl'
         }
+        testCompile project(":spring-web").sourceSets.test.output
     }
 
     // pick up DispatcherServlet.properties in src/main