Fix-ups for next NDT package

These are the fixes for the next public, m-lab packaged version of NDT.

Primary changes:
 * use 3.6.4-3.6.4.2 version in SVN rather than the published 3.6.4 package (closer to current version on M-lab)
 * add support for jar signing for a future release (& changing package for java version)
 * add web100-pcap patch to fix DNS "reverse-lookup" bug.

Despite running through every version of NDT, the 'reverse-lookup' bug affects all of them.  I suspect but cannot establish that someone changed the source to version running on M-lab but no one can confirm this.  Applying this patch fixes it.