Merge pull request #27 from esl/master

Changes in tutorials, add pictures and announcment
2014 T7: fix wrong name typo
2014 T3: consistently use the 3rd person
2014/tutorial-schedule: fix spelling error
2014 T12: fix filename error
improve image layout in sessions

Undo column gutter change of 4e16205199211c56ebc21a8c94a839cff30c2c1b.
It was desired only in 3 columns on main conference pages, but doesn’t
look right in the columns created for images.
2014 T11: remove unnecessary sentence

We now have paragraph for second speaker, so this sentence obsolete.
2014/tutorial-schedule: fix formatting

Page extension was .html, but it wasn’t an html file. Renamed to .md,
put into grid, and used lists for pricing.
Simplify yallop bio.
No need to escape apostrophes.
Merge pull request #28 from yallop/bio-tweaks

Bio tweaks