Correct the num of pages when total_posts exactly equals to per_page

[hugozhu]

Also fix the active page in paginator_navigation

Before the fix, I got errors as below: 2013/03/04 00:03:28 compile.go:589: 3 /posts/ paginator 4 2013/03/04 00:03:28 compile.go:592: page number = 1 2013/03/04 00:03:28 compile.go:592: page number = 2 2013/03/04 00:03:28 compile.go:592: page number = 3 2013/03/04 00:03:28 compile.go:592: page number = 4 2013/03/04 00:03:28 node.go:88: What? 0xf8401cac00 2013/03/04 00:03:28 context.go:228: Not Support kind=func 2013/03/04 00:03:28 context.go:228: Not Support kind=func 2013/03/04 00:03:28 node.go:88: What? 0xf8401cac00 2013/03/04 00:03:28 node.go:88: What? 0xf8401cac40 2013/03/04 00:03:28 context.go:228: Not Support kind=func 2013/03/04 00:03:28 context.go:228: Not Support kind=func 2013/03/04 00:03:28 node.go:88: What? 0xf8401cac40 2013/03/04 00:03:28 node.go:88: What? 0xf8401cac80 2013/03/04 00:03:28 context.go:228: Not Support kind=func 2013/03/04 00:03:28 context.go:228: Not Support kind=func 2013/03/04 00:03:28 node.go:88: What? 0xf8401cac80 2013/03/04 00:03:28 node.go:88: What? 0xf8401cacc0 2013/03/04 00:03:28 context.go:228: Not Support kind=func 2013/03/04 00:03:28 context.go:228: Not Support kind=func 2