Add new features to vagrant

* growl notifier to notify from guest to host
* vagrant rsync-back plugin to sync host from guest
* edit README
Fix ruby_gntp only in development env
Add agent and owner dashboard views
Update Property views with Category and Detail N:M
Fix user-realestate association
Add association Realestate has many Properties
Fix agent permissions
Update factories with new assoc

* User :agent creates a new Realestate
* Realestate :with_agent creates a new Agent
Merge pull request #4 from remanager/vagrant_new_features

Add new features to vagrant
Add links to agent dashboard view
Merge branch 'develop' into models

* develop:
  Fix ruby_gntp only in development env
  Add new features to vagrant
Add host to run better_errors in vagrant
Add to_s method to models
WIP: agent add property views