Update blog/2013-02-16-kmeans-clustering-I.lhs

Missing close paren
Update blog/2013-02-17-kmeans-clustering-II.lhs
Possessive -> plural
Merge pull request #36 from abakst/patch-2

Possessive -> plural. Awesome -- thanks Alexander!
Merge pull request #35 from abakst/patch-1

Missing relative pronoun -- eeks, can't believe I missed that. thanks!
Merge pull request #34 from Ptival/patch-1

Thanks!
merge upstream blog updates