Fix Heartbleed vulnerability on Training VM.

This is an ugly hack that will have to do until there is a new ISO.
It's early enough in the kickstart to mitigate any risk of any actual
information being compromised (not that there's anything sensitive here).
Merge pull request #245 from klynton/heartbleed

Fix Heartbleed vulnerability on Training VM.
always grab the latest p-t-b commit during init
Merge pull request #246 from casharma/buildissue/ptbcloning

always grab the latest p-t-b commit during init
Gross script to reset ssl certs

I got tired of doing this by hand on the occasion when I forgot to fix
ntp before installation.
Add warning/usage message
Add master check
Add message to reset client certs
Enables simplified classroom install

This will enable more classroom automation. The only thing it does by
default now is enable time management.

Functionality it provides:
  * students can run a script to automatically configure the classroom.
    It will ask their name and the master's IP and then make magic
    happen. This takes about 45 seconds to complete.
  * instructors can enable $autosetup on the fundamentals class. This
    will manage student's environments and modulepath setting
    automatically. (With the exception of the almost nonexistant case
    where a student is added to multiple teams.)
  * ntp management is enabled by default. The master runs an ntp server
    and all student machines sync from it. The classroom setup script
    automatically syncs, so time problems should never happen again.
  * Pass $offline => true to the fundamentals class and ntp will be
    configured to run in standalone mode.

This is *not* enabled by default, but will be available for
experimentation by instructors willing to troubleshoot and fix breakage.

Based on feedback, this will possibly eliminate most of the classroom
setup labs and somewhat simplify the git workflow lesson.
Merge pull request #247 from binford2k/feature/reset_certificates

Gross script to reset ssl certs
Remove classroom alias...

since it wouldn't work anyway
Merge pull request #248 from binford2k/feature/simplified_install

Enables simplified classroom install
Merge branch 'master' into trainvm-16

* master:
  Remove classroom alias...
  Enables simplified classroom install
  Add message to reset client certs
  Add master check
  Add warning/usage message
  Gross script to reset ssl certs
  always grab the latest p-t-b commit during init
  Fix Heartbleed vulnerability on Training VM.