Updated typo  PremailerRails -> Premailer::Rails and updated doco to match current state of premailer-rails3 (deprecated, use premailer-rails now).
Updated typo  PremailerRails -> Premailer::Rails and updated doco to match current state of premailer-rails3 (deprecated, use premailer-rails now).

glebm/rails_email_preview,restorando/rails_email_preview,bandzoogle/rails_email_preview,fgbreel/rails_email_preview,bandzoogle/rails_email_preview,glebm/rails_email_preview,0xCCD/rails_email_preview,0xCCD/rails_email_preview,restorando/rails_email_preview,fgbreel/rails_email_preview,bandzoogle/rails_email_preview,restorando/rails_email_preview,fgbreel/rails_email_preview,glebm/rails_email_preview