Grant leader/revoke leader operations.

Project leaders can grant members leadership roles, and revoke leaders
to ordinary members.

Project leaders cannot revoke their own leadership role.

Institute delegates now have full edit access to projects in their
institute. This includes:

* Including granting/revoking leadership role.
* Inviting users to project.
* Removing members from project.

This was done because it is the institute delegate who approves the
initial project application in initial project leader.

Ensure project invite button only displayed when the user is allowed
to invite new member to project.

Change-Id: I54d8a3d30cf723d141a46153860abc2d23aff6e2