Crew signup

[rmil]

Lots of new endpoints added to now allow individual users to sign-up to events now. Also, a couple more admin / director endpoints to use.

• Numerous checks to ensure current user has permission to change their role
• Quick add / delete crew to positions
• More update endpoints
• More documentation
• Slight re-arrangement of routing so things are more grouped together, although not all of the "context" is used for every request i.e. if your updating the crew for an event, it only considers the crewid not the rest of the URL, later versions probably could take advantage to reduce the amount of searching / interpreting needs to be done for the validating.

Resolves #7