Adding documentations for the Jenkins file

Change-Id: I2ff71c4a787901b80401bb53117572f9c58ef6d0
diff --git a/TestON/JenkinsFile/Overall_Graph_Generator b/TestON/JenkinsFile/Overall_Graph_Generator
index f08f18a..e96a65f 100644
--- a/TestON/JenkinsFile/Overall_Graph_Generator
+++ b/TestON/JenkinsFile/Overall_Graph_Generator
@@ -1,18 +1,46 @@
+// Copyright 2017 Open Networking Foundation (ONF)
+//
+// Please refer questions to either the onos test mailing list at <onos-test@onosproject.org>,
+// the System Testing Plans and Results wiki page at <https://wiki.onosproject.org/x/voMg>,
+// or the System Testing Guide page at <https://wiki.onosproject.org/x/WYQg>
+//
+//     TestON is free software: you can redistribute it and/or modify
+//     it under the terms of the GNU General Public License as published by
+//     the Free Software Foundation, either version 2 of the License, or
+//     (at your option) any later version.
+//
+//     TestON is distributed in the hope that it will be useful,
+//     but WITHOUT ANY WARRANTY; without even the implied warranty of
+//     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+//     GNU General Public License for more details.
+//
+//     You should have received a copy of the GNU General Public License
+//     along with TestON.  If not, see <http://www.gnu.org/licenses/>.
+
+// This is the Jenkins script for manual-graph-generator-overall
+
 #!groovy
+
+// read the dependency functions.
 funcs = evaluate readTrusted( 'TestON/JenkinsFile/dependencies/JenkinsCommonFuncs.groovy' )
 test_lists = evaluate readTrusted( 'TestON/JenkinsFile/dependencies/JenkinsTestONTests.groovy' )
 fileRelated = evaluate readTrusted( 'TestON/JenkinsFile/dependencies/JenkinsPathAndFiles.groovy' )
 
 fileRelated.init()
+
+// set the file and directory paths.
 stat_graph_generator_file = fileRelated.histogramMultiple
 pie_graph_generator_file = fileRelated.pieMultiple
 graph_saved_directory = fileRelated.jenkinsWorkspace + "postjob-VM/"
 
+// init trend which will generate the pie and histogram graphs to be VM.
 funcs.initializeTrend( "VM" )
 
 onos_branch = params.ONOSbranch
 AllTheTests = test_lists.getAllTheTests("")
 
+// generate the graph and post the result on TestStation-VMs. Right now, all the pie and histograms are saved
+// on VM.
 funcs.generateStatGraph( "TestStation-VMs",
                          onos_branch,
                          AllTheTests,