Fix more SQL migrations to use raw commands

gitlab-org/gitlab-development-kit#109

db/migrate/20130315124931_user_color_scheme.rb

 class UserColorScheme < ActiveRecord::Migration
+  include Gitlab::Database
+
   def up
     add_column :users, :color_scheme_id, :integer, null: false, default: 1
-    User.where(dark_scheme: true).update_all(color_scheme_id: 2)
+    execute("UPDATE users SET color_scheme_id = 2 WHERE dark_scheme = #{true_value}")
     remove_column :users, :dark_scheme
   end
 

db/migrate/20131112220935_add_visibility_level_to_projects.rb

 class AddVisibilityLevelToProjects < ActiveRecord::Migration
+  include Gitlab::Database
+
   def self.up
     add_column :projects, :visibility_level, :integer, :default => 0, :null => false
-    Project.where(public: true).update_all(visibility_level: Gitlab::VisibilityLevel::PUBLIC)
+    execute("UPDATE projects SET visibility_level = #{Gitlab::VisibilityLevel::PUBLIC} WHERE public = #{true_value}")
     remove_column :projects, :public
   end
 
   def self.down
     add_column :projects, :public, :boolean, :default => false, :null => false
-    Project.where(visibility_level: Gitlab::VisibilityLevel::PUBLIC).update_all(public: true)
+    execute("UPDATE projects SET public = #{true_value} WHERE visibility_level = #{Gitlab::VisibilityLevel::PUBLIC}")
     remove_column :projects, :visibility_level
   end
 end

db/migrate/20140313092127_migrate_already_imported_projects.rb

 class MigrateAlreadyImportedProjects < ActiveRecord::Migration
+  include Gitlab::Database
+
   def up
-    Project.where(imported: true).update_all(import_status: "finished")
-    Project.where(imported: false).update_all(import_status: "none")
+    execute("UPDATE projects SET import_status = 'finished' WHERE imported = #{true_value}")
+    execute("UPDATE projects SET import_status = 'none' WHERE imported = #{false_value}")
     remove_column :projects, :imported
   end
 
   def down
     add_column :projects, :imported, :boolean, default: false
-    Project.where(import_status: 'finished').update_all(imported: true)
+    execute("UPDATE projects SET imported = #{true_value} WHERE import_status = 'finished'")
   end
 end

db/migrate/20141007100818_add_visibility_level_to_snippet.rb

@@ -2,8 +2,8 @@ class AddVisibilityLevelToSnippet < ActiveRecord::Migration
   def up
     add_column :snippets, :visibility_level, :integer, :default => 0, :null => false
 
-    Snippet.where(private: true).update_all(visibility_level: Gitlab::VisibilityLevel::PRIVATE)
-    Snippet.where(private: false).update_all(visibility_level: Gitlab::VisibilityLevel::INTERNAL)
+    execute("UPDATE snippets SET visibility_level = #{Gitlab::VisibilityLevel::PRIVATE} WHERE private = true")
+    execute("UPDATE snippets SET visibility_level = #{Gitlab::VisibilityLevel::INTERNAL} WHERE private = false")
 
     add_index :snippets, :visibility_level
 
@@ -13,8 +13,8 @@ class AddVisibilityLevelToSnippet < ActiveRecord::Migration
   def down
     add_column :snippets, :private, :boolean, :default => false, :null => false
 
-    Snippet.where(visibility_level: Gitlab::VisibilityLevel::INTERNAL).update_all(private: false)
-    Snippet.where(visibility_level: Gitlab::VisibilityLevel::PRIVATE).update_all(private: true)
+    execute("UPDATE snippets SET private = false WHERE visibility_level = #{Gitlab::VisibilityLevel::INTERNAL}")
+    execute("UPDATE snippets SET private = true WHERE visibility_level = #{Gitlab::VisibilityLevel::PRIVATE}")
 
     remove_column :snippets, :visibility_level
   end