Add write control on repository from Redmine interface

* new methods to add/remove rights in app/models/role.rb
  * some unit tests
  * add write check in Redmine.pm

To keep compatibility migration add write rights to non builtin roles
but default clean install give write access only to manager and
developer, not to reporter.


git-svn-id: http://redmine.rubyforge.org/svn/branches/nbc@1791 e93f8b46-1217-0410-a6f0-8f06a7374b81

app/models/role.rb

@@ -36,7 +36,7 @@ class Role < ActiveRecord::Base
   has_many :members
   acts_as_list
   
-  serialize :permissions
+  serialize :permissions, Array
   attr_protected :builtin
 
   validates_presence_of :name
@@ -49,9 +49,27 @@ class Role < ActiveRecord::Base
   end
   
   def permissions=(perms)
-    perms = perms.collect {|p| p.to_sym unless p.blank? }.compact if perms
+    perms = perms.collect {|p| p.to_sym unless p.blank? }.compact.uniq if perms
     write_attribute(:permissions, perms)
   end
+
+  def add_permission!(*perms)
+    self.permissions = [] unless permissions.is_a?(Array)
+
+    permissions_will_change!
+    perms.each do |p|
+      p = p.to_sym
+      permissions << p unless permissions.include?(p)
+    end
+    save!
+  end
+
+  def remove_permission!(*perms)
+    return unless permissions.is_a?(Array)
+    permissions_will_change!
+    perms.each { |p| permissions.delete(p.to_sym) }
+    save!
+  end
   
   def <=>(role)
     position <=> role.position