Remove support for deprecated password-hashing algorithm

* Remove all methods implementing and checking for the old algorithm
* Document a pre-upgrade step to check for remaining obsolete passwords
* Remove config.salt

lib/tasks/tracks.rake

@@ -24,15 +24,5 @@ namespace :tracks do
       user.errors.full_messages.each { |msg| puts "- #{msg}\n" }
     end
   end
-
-  desc 'Check all passwords for deprecated hashes'
-  task :check_passwords => :environment do
-    puts "The following users have deprecated password hashes:"
-    User.all.each do |user|
-      if user.uses_deprecated_password?
-        puts "  #{user.login}"
-      end
-    end
-  end
 end
 

lib/tracks/config.rb

@@ -1,10 +1,6 @@
 module Tracks
   
   class Config
-    
-    def self.salt
-       SITE_CONFIG['salt']
-    end
 
     def self.auth_schemes
        SITE_CONFIG['authentication_schemes'] || []
@@ -28,4 +24,4 @@ module Tracks
     
   end
   
-end
+end