Added generation of sha1 of distro archive to build.

build.gradle

@@ -141,12 +141,15 @@ task dist (type: Zip) {
     into('docs/reference') {
         from docsDir
     }
-
     into('dist') {
         from coreModuleProjects().collect { project -> project.libsDir }
     }
 }
 
+dist.doLast {
+    ant.checksum(file: archivePath, algorithm: 'SHA1', fileext: '.sha1')
+}
+
 dist.dependsOn apidocs, ':manual:doc'
 dist.dependsOn subprojects.collect { "$it.path:assemble" }