Tidy up various news posts for typos and punctuation

_posts/2016-07-26-advert.md

_posts/2016-09-01-newmember.md

_posts/2016-10-03-papers.md

_posts/2016-11-23-dagstuhl.md

_posts/2016-12-15-Dolby.md

_posts/2017-01-13-Pedro_viva.md

_posts/2017-02-01-Gian_viva.md

_posts/2017-02-11-INVEST.md

_posts/2017-02-14-NCSC_official_opening.md

_posts/2017-04-24-Dosualdo.md

_posts/2017-05-03-consistency.md

_posts/2017-05-08-aarhus.md

_posts/2017-06-13-csf.md