lock & unlock rosters admin feature
redirect to install from login page if admin not found
add lock roster feature to frontend
re-word locked message on frontend
add Mandrill support
update installation and upgrade
update version

v3.1.1
Merge pull request #106 from stoopkid1/Remove-Create-Admin-Link-from-Login-page

Remove create admin link, Mandrill SMTP support & Roster Locking