Added support in PagerOptions for custom displaytext on next/previous links.

Instead of << and >> you want the words "Next" and "Previous".
Example of usage:
@Html.Pager(Model.PageSize, Model.PageNumber, Model.TotalItemCount).Options(o => o.AddRouteValue("categoryname", ViewBag.CategoryDisplayName)
			.SetNextPageText("Next")
			.SetPreviousPageText("Prevoius"))
Changed pull request #40 a little bit:
  Changed spaces to tabs.
  Fixed typo.
  Added simple unit test.
Added custom previous-next text option to Bootstrap example.
See also pull request #40.
Merge branch 'customnextprevious'