Updates django_manage so it populates VIRTUAL_ENV

Virtualenv's activate script sets the VIRTUAL_ENV environment variable to the path of the virtualenv. Checking this variable is a reasonably common way to verify that execution is happening in a virtualenv. It would be convenient if this module's virtualenv handling set this environment variable.
Building Ansible deb requires setuptools
Set default vg_options to empty string
BUGFIX 7811: Adding file existence check when performing mysql import on a .gz or .bz2 file, otherwise Ansible will not notice that the underlying *nix command silently died.
Merge pull request #7809 from rouge8/patch-1

Building Ansible deb requires setuptools
BUGFIX 1178: Adding better existence check in one place.  db_import now fails fast if target does not exist b/c no point going further without the target.
Merge pull request #7808 from joelcrocker/patch-1

Updates django_manage so it populates VIRTUAL_ENV
Merge pull request #7810 from rivik/lvg_options_fix

Set default vg_options to empty string
Merge pull request #7814 from scottbrown/bugfix-7811-mysql_import_does_not_perform_dump_existence_check

BUGFIX for Issue 7811: Adding file existence check when performing mysql import on...