Gradle 'api' task depends on 'jar' tasks

Update the gradle 'api' task to depend on the 'jar' task of all
subprojects. This intern ensures that the 'asmRepackJar' and
'cglibRepackJar' tasks run which is critical for JavaDoc
generation.

build.gradle

@@ -788,6 +788,11 @@ configure(rootProject) {
 		description = "Generates aggregated Javadoc API documentation."
 		title = "${rootProject.description} ${version} API"
 
+		dependsOn {
+			subprojects.collect {
+				it.tasks.getByName("jar")
+			}
+		}
 		options.memberLevel = org.gradle.external.javadoc.JavadocMemberLevel.PROTECTED
 		options.author = true
 		options.header = rootProject.description