Constituency and Election dropdowns work; tidied up Election profile page; added Edit Member Profile feature

Made the Election profile page look nicer.

Both dropdowns now work. Constituency dropdown takes you to the selected
constituencies profile page, where you can select from an Election
dropdown that is only populated with elections within the constituency.
The key for making that work was just _set.all:

{% for election in constituency.election_set.all %}

<option value="/elections/get/{{ election.id }}">{{ election.name
}}</option>
            {% endfor %}

Also added the ability to change a member's own profile information.
This uses Django's UpdateView class, which I don't entirely understand.
Hopefully the UpdateView class can work to allow an auth-user to update
their candidate profile, and an auth-user-moderator to update their
election page.