Simplified Workflow: add option to disable the creation of new statuses

As a JIRA administrator,

I'd like to be able to disable the creation of new statuses by standard users through the Simplified Workflow's 'Add Status' button

so that I can:

• avoid the creation of effectively duplicated status names like "To Do" & "TODO", or Testing & Test & Tested & In Test & Integration Test
• make easier multi-project JQL queries to retrieve meaningful info based on statuses
• make more maintainable the order in which statuses are displayed in gadgets and JQL ORDER BY clause.
• avoid the creation of statuses for trying to store info when it would be better to use anything else instead (labels, the resolution field, a custom field...)