Add .gitignore file

When you want to see 'git status' including ignored files run:

  git status --ignored
Feature #2562: New Zone pool in core
Feature #2562: New Zone pool in ruby oca and cli
Feature #2565: New method in acl manager to delete acl rules directly, instead of by id
Feature #2565: Manage resource providers in oned
Feature #2565: Manage resource providers in the CLI
Feature #2562: Manage zones in suntone

Fow now, the tab only lists and deletes zones. We'll need to
do a creation wizard, decide if we want actions like rename,
update, etc.
Feature #2562: Manage resource providers in sunstone group tab
Feature #2565: Fix bug in onegroup show
Feature #2570: Extend the group creation wizard.

TODO: Send a new json using the new input values,
cluster selection table.
Feature #2570: Add Server side funtionality
Feature #2570: Fix syntax error
Feature #2570: Fix bug in user wizard
Feature #2570: Add admin group and admin user to json sent in group wizard
Feature #2570: Add cluster table in group creation wizard
Feature #2570: More server side changes
Feature #2570: Fix syntax error II
Feature #2570: Fix for new group functionality
Feature #2570: Add zone tabs to group creation wizard

Only one hardcoded for now
Feature #2570: Improve CLI support for new group functionality