add pagination for getting log entries from wikis

lib/gollum/pagination.rb

@@ -0,0 +1,32 @@
+module Gollum
+  module Pagination
+    def self.included(klass)
+      klass.extend ClassMethods
+      class << klass
+        attr_accessor :per_page
+      end
+      klass.per_page = 30
+    end
+
+    module ClassMethods
+      def page_to_skip(page)
+        ([1, page.to_i].max - 1) * per_page
+      end
+
+      def log_pagination_options(options = {})
+        skip = page_to_skip(options.delete(:page))
+        options[:max_count] = [options.delete(:per_page).to_i, per_page].max
+        options[:skip]      = skip if skip > 0
+        options
+      end
+    end
+
+    def page_to_skip(page)
+      self.class.page_to_skip(page)
+    end
+
+    def log_pagination_options(options = {})
+      self.class.log_pagination_options(options)
+    end
+  end
+end