Simplify person serialization

Use the existing fields array to loop through and gather the relevant
bits of information that we want to persist back to the API.
Simplify person population

When the save is complete, loop through the existing fields array and
populate the person view page.
Allow mongoose to be put into debug model

By setting the MONGOOSE_DEBUG environment variable, mongoose will print
out all the database operations being performed.
Intercept person PUT requests and extract party

When a person is PUT to the API we extract the organization field from
the body and use it to associate the person with an organization which
represents their "primary" party.
Make sure organization fields get sent to the API

Without this the client side javascript doesn't process these fields
correctly.
Populate persons party before rendering template
Allow editing persons party name

When the persons party is edited this updates the existing party rather
than creating a new one. The party that appears on the person page has a
'_primary' field that is set to true.
Add persons constituency to the page
Trim text before populating form

Because there is whitespace within the paragraph that we take the value
from, we need to remove it before populating the form inputs.
Load underscore properly using require.js

Without this underscore appears to be there most of the time, but
because it's loaded async there's a slim chance that it won't be there.
By making the dependency explicit using require.js we avoid any
potential problems.
Include instance name in confirmation email

Add the slug name to the text of the email as well as including it in
the confirmation URL.

Fixes #455
make create new organization an actual page

make person-new action into entity-new action and add in switching code
so it works with organizations as well.
update new organization template
apply new person html to organisation page

as part of restyle of page to move lots of the non essential details
into tabs etc
reformat entity-new to make subsequent edits clearer

split out define stuff per line and indent everything accordingly
Add autosuggest for organization name on new org page

to help prevent duplicate organization creation.
Needs styling
make organization classification a select2 dropdown

So you get suggestions of existing classifications but can also create
your own.
Needs styling.
remove unhelpful breadcrumbs from organization page header
ask for organization type if not present

and clicking on it activates editing mode
update html for items in tabs
JSON API -> Get this data as toolbar button text

Just a bit more friendly