`vagrant up` fix - only automatically creates dev env first time run on a workspace.

vagrant:
  - check actual IP;
  - only init machine first time, just as native installations;
  - add .bash_profile to permissions fixup;
  - cleanup excessive newlines in making .bash_profile;

README:
  - include admin & debugging use;
  - info about re-initializing VM & manually running create-dev-env.sh;
  - add django admin & debug_toolbar setting info