Fix scopes request by UI to include 'users' which is needed for post detail
First cut at returning ACL info in the API, and tweaking the UI based on permissions

Return ‘allowed_methods’ in the Posts API
Check for allowed methods in post list and post detail to show/hide
actions
Fix trailing spaces in Post model and API
Extend 'allowed_methods' field to all API calls

Move allowed methods code to Ushahidi_Api class.
Add calls to allowed_methods to all the API classes.
Merge pull request #164 from ushahidi/api-permissions-meta

Return resource permissions in the API, and user this to show/hide action buttons in the UI