Create a default tmux session only when none defined in tmux.conf

Signed-off-by: Sorin Ionescu <sorin.ionescu@gmail.com>
Support $PYTHONUSERBASE per PEP 370

Signed-off-by: Sorin Ionescu <sorin.ionescu@gmail.com>
Add in a check for java_home around EC2 tools block
Merge commit 'bf9dbfd5b95c44b14a8a6af8ecf965ecea50fb29' into develop