Prepare for the 0.7.3 release.

If neither the java plugin nor the android plugin was found, the error
message will instruct the user to stay away from Gradle's new plugin DSL
because of #40.

README.md

@@ -2,7 +2,7 @@
 probably reading the documentation for the __HEAD revision__, which may not
 apply to the released version you are using. To read the documentation of a
 released version, you will need to switch to the corresponding release tag,
-e.g., [v0.7.2](https://github.com/google/protobuf-gradle-plugin/tree/v0.7.2).
+e.g., [v0.7.3](https://github.com/google/protobuf-gradle-plugin/tree/v0.7.3).
 
 # Protobuf Plugin for Gradle
 The Gradle plugin that compiles Protocol Buffer (aka. Protobuf) definition
@@ -17,15 +17,15 @@ For more information about the Protobuf Compiler, please refer to
 [Google Developers Site](https://developers.google.com/protocol-buffers/docs/reference/java-generated?csw=1).
 
 ## Latest Version
-The latest version is ``0.7.2``. It is available on Maven Central. To add
+The latest version is ``0.7.3``. It is available on Maven Central. To add
 dependency to it:
 ```gradle
 buildscript {
   repositories {
     mavenCentral()
   }
   dependencies {
-    classpath 'com.google.protobuf:protobuf-gradle-plugin:0.7.2'
+    classpath 'com.google.protobuf:protobuf-gradle-plugin:0.7.3'
   }
 }
 ```
@@ -39,7 +39,7 @@ buildscript {
     }
   }
   dependencies {
-    classpath 'com.google.protobuf:protobuf-gradle-plugin:0.7.2-SNAPSHOT'
+    classpath 'com.google.protobuf:protobuf-gradle-plugin:0.7.4-SNAPSHOT'
   }
 }
 ```
@@ -53,7 +53,7 @@ buildscript {
     mavenLocal()
   }
   dependencies {
-    classpath 'com.google.protobuf:protobuf-gradle-plugin:0.7.2-SNAPSHOT'
+    classpath 'com.google.protobuf:protobuf-gradle-plugin:0.7.4-SNAPSHOT'
   }
 }
 ```
@@ -62,6 +62,9 @@ buildscript {
 
 ### Adding the plugin to your project
 
+:warning: this plugin __does not__ work under the new plugins DSL of Gradle
+(#40). Use the traditional `apply` method instead.
+
 In Java projects, you must apply the java plugin before applying the Protobuf
 plugin:
 

build.gradle

@@ -20,7 +20,7 @@ apply plugin: "com.gradle.plugin-publish"
 apply plugin: 'signing'
 
 group = 'com.google.protobuf'
-version = '0.7.2'
+version = '0.7.3'
 
 ext.isReleaseVersion = !version.endsWith("SNAPSHOT")
 

src/main/groovy/com/google/protobuf/gradle/ProtobufPlugin.groovy

@@ -60,7 +60,9 @@ class ProtobufPlugin implements Plugin<Project> {
         }
 
         if (!project.plugins.hasPlugin('java') && !Utils.isAndroidProject(project)) {
-            throw new GradleException('Please apply the Java plugin or the Android plugin first')
+            throw new GradleException('Please apply the Java plugin or the Android plugin first.'
+                + ' This error may also be a result of using the new Gradle plugins DSL.'
+                + ' Please use the traditional "apply" function as described in README.md.')
         }
 
         // Provides the osdetector extension