UserName Availability check on Registration Page

My first checkin to this project, this is a super small update.  I added
a new CSS file called forms which is being used to stored
success/failure validation stuff.  There is one function in the
regisration.cshtml page that should be moved out to a more global file
but didn't want to jump out on a limb.
Fix for object ref when assigning.

When an admin is logged in and tries to assign the account to a crisis,
an object ref error comes up from the missing person record.
Spelling Fix
Merge pull request #121 from jasonjanofsky/master

UserName Availability check on Registration Page