fix random issue by modifying java.security file

This fixes the issue with blocking random calls by modifying java.security with the workaround described in [JDK-6202721](http://bugs.java.com/view_bug.do;jsessionid=ff625daf459fdffffffffcd54f1c775299e0?bug_id=6202721).  This is essentially the same fix that @zxqfox mentioned in comments for #14, but taken one layer deeper by modifying java.security instead of specifying the parameter on the command line with -D.