Add i18n to page_entries_info helper method and use count param in human method to pluralize correctly

Hi, I just change some lines of page_entries_info for fix to problems with translations.

By one side, `pluralize` is for calculate names by rails conventions, not for translations. For i18n I've used the `count` parameter: http://guides.rubyonrails.org/i18n.html#pluralization

By other side, it's better put "entry" name in locale file (en.yml), then it can be translated for other locales. Of course, using the `count` parameter too, for pluralize if necessary.

I hope you find these changes usefull. Cheers.