added pure python re-implementation of sshrc

It's way more complicated than the shell, but it was a good learning
experience.

We use cPickle to bundle, then bz2 compress and send with base64 encoding.
on the client we untar without chaining owner or utime so make sure
the untarred files are correct

We stuff all the data into the $TERM variable to avoid displaying the
base64 encoded data in 'ps'.

The try/finally should clean after the client bash exists.
TODO: test with SIGHUP handler

Signed-off-by: Ross Brattain <ross.b.brattain@intel.com>