Standardize Build

The build now uses spring build conventions to simplify the build

Fixes gh-4284

buildSrc/src/main/groovy/MavenBomTask.groovy

@@ -6,7 +6,7 @@ import org.gradle.api.tasks.*
 
 public class MavenBomTask extends DefaultTask {
 
-	Set<Project> projects
+	Set<Project> projects = []
 
 	File bomFile
 
@@ -52,4 +52,4 @@ public class MavenBomTask extends DefaultTask {
 			}
 		}
 	}
-}
+}

buildSrc/src/main/groovy/aspectj/AspectJPlugin.groovy

@@ -26,15 +26,11 @@ class AspectJPlugin implements Plugin<Project> {
 	void apply(Project project) {
 		project.plugins.apply(JavaPlugin)
 
-		if (!project.hasProperty('aspectjVersion')) {
-			throw new GradleException("You must set the property 'aspectjVersion' before applying the aspectj plugin")
-		}
-
 		if (project.configurations.findByName('ajtools') == null) {
 			project.configurations.create('ajtools')
 			project.dependencies {
-				ajtools "org.aspectj:aspectjtools:${project.aspectjVersion}"
-				optional "org.aspectj:aspectjrt:${project.aspectjVersion}"
+				ajtools "org.aspectj:aspectjtools"
+				optional "org.aspectj:aspectjrt"
 			}
 		}