Form for lender signup, lender and pledge models

Very similar to what you did for listings.
Currently the permalink calls the lender signup view directly rather
than going through the lender signup controller.  It seems like we need
to allow either a lender to go in through some front door or through
some permalink in general, though maybe for v1 permalink only is good
enough.

Also, I am not using the session concept on these.  The pledge amount
goes through as a hidden field in the lender signup form (though I have
used code igniter idioms throughout at this point).  I agree that the
session concept seems neat/important but I am not sure if you 1) pledge
on a link, 2) exit the signup flow back to homepage and then 3) attempt
to sign up through generic signup rather than permalink, whether we
would actually want to remember your pledge info in that case?  It may
not matter if only signup is through permalink.

New tables for your db:
wefinance/lenders
lender_id: primary, bigint(20) unsigned
email: text
state:tiny_int(4)

wefinance/pledges
pledge_id:bigint(20) unsigned primary
lender_id:bigint(20) unsigned primary (but maybe shouldn’t be primary?)
listing_id:bigint(20) unsigned primary (also maybe not primary?)
pledge_amount: mediumint(9)
state: tinyint(4)