add LICENSE reference in README and in guide

README.md

@@ -45,3 +45,10 @@ See the Plugin documentation (sources under src/docs/), or the "live" version he
 Home Page for the project (and sources) on GitHUB:
 [grails-akka](https://github.com/smartiniOnGitHub/grails-akka/)
 
+
+License
+=======
+
+Licensed under the terms of the [Apache License, Version 2.0](http://www.apache.org/licenses/LICENSE-2.0)
+
+

src/docs/guide/1 Introduction.gdoc

@@ -6,3 +6,8 @@ This plugin makes it easy to use [Akka|http://akka.io/] Actors (both local and r
 
 All using standard Groovy / Java code.
 
+
+h4. License
+
+Licensed under the terms of the [Apache License, Version 2.0|http://www.apache.org/licenses/LICENSE-2.0]
+

src/docs/guide/2 Usage.gdoc

@@ -4,7 +4,7 @@ First you need to install the plugin into a Grails application:
 using the recommended way, configure it as a dependency in @BuildConfig.groovy@:
 {code}
 plugins {
-    compile ':akka:0.5'
+    compile ':akka:<plugin version>'
 }
 {code}
 
@@ -22,6 +22,7 @@ grails.servlet.version = "3.0"
 {code}
 
 * Akka 2.x (as specified in plugin descriptor) and related dependencies,
-all downloaded from the Central Maven Repository (that must be enabled), and the Typesafe Maven Repository (defined inside the plugin).
+all downloaded from the Central Maven Repository (that must be enabled),
+and the Typesafe Maven Repository (defined inside the plugin).