Whitespace cleanup

* remove trailing whitespace
* remove empty lines at the end of files

plugins/docker/docker_memory

@@ -81,7 +81,7 @@ if (defined $ARGV[0] and $ARGV[0] eq "config")
    print "graph_vlabel Bytes\n";
    print "graph_category virtualization\n";
    print "graph_info This graph shows docker container memory usage.\n";
-   
+
    foreach(@result)
    {
       print "$$_{'name'}.label $$_{'name'}\n";