Rails4: replace deprecated #connection from Issue model

DEPRECATION WARNING: #connection is deprecated in favour of accessing it via the class.

git-svn-id: http://svn.redmine.org/redmine/trunk@12715 e93f8b46-1217-0410-a6f0-8f06a7374b81
Rails4: replace deprecated #connection from IssueCustomField model

DEPRECATION WARNING: #connection is deprecated in favour of accessing it via the class.

git-svn-id: http://svn.redmine.org/redmine/trunk@12716 e93f8b46-1217-0410-a6f0-8f06a7374b81
Rails4: replace deprecated #connection from IssueQuery model

DEPRECATION WARNING: #connection is deprecated in favour of accessing it via the class.

git-svn-id: http://svn.redmine.org/redmine/trunk@12717 e93f8b46-1217-0410-a6f0-8f06a7374b81
Rails4: replace deprecated #connection from Repository model

DEPRECATION WARNING: #connection is deprecated in favour of accessing it via the class.

git-svn-id: http://svn.redmine.org/redmine/trunk@12718 e93f8b46-1217-0410-a6f0-8f06a7374b81
Rails4: replace deprecated #connection from Project model

DEPRECATION WARNING: #connection is deprecated in favour of accessing it via the class.

git-svn-id: http://svn.redmine.org/redmine/trunk@12719 e93f8b46-1217-0410-a6f0-8f06a7374b81
Rails4: replace deprecated #connection from Query model

DEPRECATION WARNING: #connection is deprecated in favour of accessing it via the class.

git-svn-id: http://svn.redmine.org/redmine/trunk@12720 e93f8b46-1217-0410-a6f0-8f06a7374b81
remove unneeded Relation#all from WorkflowsController

git-svn-id: http://svn.redmine.org/redmine/trunk@12721 e93f8b46-1217-0410-a6f0-8f06a7374b81
remove unneeded Relation#all from IssuePriority model

git-svn-id: http://svn.redmine.org/redmine/trunk@12722 e93f8b46-1217-0410-a6f0-8f06a7374b81
remove unneeded Relation#all from Mailer model

git-svn-id: http://svn.redmine.org/redmine/trunk@12723 e93f8b46-1217-0410-a6f0-8f06a7374b81
remove unneeded Relation#all from IssueQuery model

git-svn-id: http://svn.redmine.org/redmine/trunk@12724 e93f8b46-1217-0410-a6f0-8f06a7374b81