Added paginationStyle parameter so that we can use it with Bootstrap 3's Pagination
http://getbootstrap.com/components/#pagination

Sample code:

@grid.PagerList(mode: WebGridPagerModes.NextPrevious | WebGridPagerModes.Numeric,
numericLinksCount: 10, paginationStyle: "pagination", previousText: "«", nextText: "»")
Merge pull request #2 from leniel/master

Added paginationStyle parameter so that we can use it with Bootstrap 3's pagination