(Bug 5073) Create pagination template

Template meant to be included within other templates; goes into
views/components.
(Bug 5265) First draft of /communities/members

* Revamped style
* Ability to filter by user roles (versus sort)
* Some stuff still hardcoded; the form elements don't work yet
(Bug 5265) Show only relevant filters/columns

E.g., moderated communities should show the moderator / unmoderated
columns. Unmoderated communities don't need those