New setting added to specify how many objects should be displayed on most paginated lists.

Default is: 25, 50, 100 (users can choose one of these values).
If one value only is entered in this setting (eg. 25), the 'per page' links are not displayed (prior behaviour).

git-svn-id: http://redmine.rubyforge.org/svn/trunk@1026 e93f8b46-1217-0410-a6f0-8f06a7374b81

app/models/setting.rb

@@ -95,6 +95,11 @@ class Setting < ActiveRecord::Base
     class_eval src, __FILE__, __LINE__
   end
   
+  # Helper that returns an array based on per_page_options setting
+  def self.per_page_options_array
+    per_page_options.split(%r{[\s,]}).collect(&:to_i).select {|n| n > 0}.sort
+  end
+  
   # Checks if settings have changed since the values were read
   # and clears the cache hash if it's the case
   # Called once per request