Add new user role as "Editor"

[RaziaMahmodi]

Add new user role as Editor. One of the functions that Editor is able to is reassigning clusters (Issue #729 ). Users that are not Editor should not see the Cluster Reassign button.
Editor is an additional user role and can be combined with another user role (Similar to Publish User) except: Mobile User, Cluster FLW. Editor cannot be a user role by itself.