Membership Application Infinite Loop Fix

Fixed a bug where the membership form would go into an infinite loop
rendering.
JavaScript Fix

Fixed a bug in AddClass and RemoveClass which was causing classes to be
duplicated or not removed.
Add/Edit Membership Type

Added the ability for administrators to add and edit membership types.

Added a link to this functionality to the administration section.
Add/Edit Organization Beautification

Added "Primary Contact Information" and "Secondary Contact Information
(Optional)" headings to the add/edit organization controller (à la the
membership application form) and removed the redundant/repetitive labels
on those fields.

Moved the "Enabled" and "Perpetual" checkboxes up so their positioning
made sense given the new headings.
Schema Change -- Notes

Added the `organization_notes` table, which will allow notes to be added
to organizations by administrators as per Jason's request.
Display Organization Beautification

Added the primary/secondary contact headers to the template which
displays organizations (used when a regular user attempts to view an
organization, or a superuser attempts to view an organization that isn't
their own).
Organization Users Listing Fix

The template which displays the list of users associated with an
organization was displaying the "Add User" link to users who did not
have the appropriate permissions (and would therefore be 403'd by
clicking through).

Removed the offending link when viewed by such users.
Notes

Added a UI for the `organization_notes` table.

Administrators will now see a listing of all notes attached to an
organization when they visit that organization's edit page (notes are
ordered by last modified time, with soonest coming first).

Administrators may click links to edit each note, or to attach a new
note.
Payment Info -- Add Payment Link

Administrators viewing organizations will now be presenting with an "Add
Payment" link at the top of the "Payment Information" section.