Update Maven usage in README to suggest annotationProcessorPaths

Also defer to the README instructions for all build tools (rather than
just Gradle)

Fixes #293
Fixes #719

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=154857182

users-guide.md

@@ -606,32 +606,11 @@ Dagger for your component.
 
 ## Using Dagger In Your Build
 
-### Gradle Users
-
 You will need to include the `dagger-2.X.jar` in your application's runtime.  In
 order to activate code generation you will need to include
 `dagger-compiler-2.X.jar` in your build at compile time. See
-the [README][gradle-installation] for more information.
-
-In a Maven project, one would include the runtime in the dependencies section of
-your `pom.xml`, and the `dagger-compiler` artifact as a dependency of the
-compiler plugin:
-
-```xml
-<dependencies>
-  <dependency>
-    <groupId>{{site.dagger.groupId}}</groupId>
-    <artifactId>dagger</artifactId>
-    <version>2.X</version>
-  </dependency>
-  <dependency>
-    <groupId>{{site.dagger.groupId}}</groupId>
-    <artifactId>dagger-compiler</artifactId>
-    <version>2.X</version>
-    <optional>true</optional>
-  </dependency>
-</dependencies>
-```
+the [README][installation] for more information.
+
 
 ## License
 
@@ -667,7 +646,7 @@ limitations under the License.
 [DI]: http://en.wikipedia.org/wiki/Dependency_injection
 [Documented]: http://docs.oracle.com/javase/7/docs/api/java/lang/annotation/Documented.html
 [Factory Pattern]: https://en.wikipedia.org/wiki/Factory_(object-oriented_programming)
-[gradle-installation]: https://github.com/google/dagger/blob/master/README.md#installation
+[installation]: https://github.com/google/dagger/blob/master/README.md#installation
 [+Gregory Kick]: https://google.com/+GregoryKick/
 [guava-optional]: https://google.github.io/guava/releases/19.0/api/docs/com/google/common/base/Optional.html
 [`javax.inject.Inject`]: http://docs.oracle.com/javaee/7/api/javax/inject/Inject.html