Adds an issues visibility level on roles (#7412).

It can be set so that users only see their own issues (created or assigned).

git-svn-id: svn+ssh://rubyforge.org/var/svn/redmine/trunk@5416 e93f8b46-1217-0410-a6f0-8f06a7374b81

test/fixtures/roles.yml

@@ -3,6 +3,7 @@ roles_001:
   name: Manager
   id: 1
   builtin: 0
+  issues_visibility: default
   permissions: |
     --- 
     - :add_project
@@ -58,6 +59,7 @@ roles_002:
   name: Developer
   id: 2
   builtin: 0
+  issues_visibility: default
   permissions: |
     --- 
     - :edit_project
@@ -102,6 +104,7 @@ roles_003:
   name: Reporter
   id: 3
   builtin: 0
+  issues_visibility: default
   permissions: |
     --- 
     - :edit_project
@@ -140,6 +143,7 @@ roles_004:
   name: Non member
   id: 4
   builtin: 1
+  issues_visibility: default
   permissions: |
     --- 
     - :view_issues
@@ -170,6 +174,7 @@ roles_005:
   name: Anonymous
   id: 5
   builtin: 2
+  issues_visibility: default
   permissions: |
     --- 
     - :view_issues