[Fix #543] Do not set tmux destroy-unattached

Signed-off-by: Sorin Ionescu <sorin.ionescu@gmail.com>
Fix git-info added/deleted count formatting typo

Signed-off-by: Sorin Ionescu <sorin.ionescu@gmail.com>
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>
Merge branch 'master' of https://github.com/sorin-ionescu/prezto

* 'master' of https://github.com/sorin-ionescu/prezto:
  Support $PYTHONUSERBASE per PEP 370
  Create a default tmux session only when none defined in tmux.conf
  Fix git-info added/deleted count formatting typo
  [Fix #543] Do not set tmux destroy-unattached