new comment font and various comment design tweaks
removing textsans bold-italic
discussion style tweaks
removing sanstext bold italics
replacing show more plus icons
renaming fs-text to fs-textsans
removing bold italic textsans font
more font renaming
making css dimensions relative to gridsystem
adding textsans font to webfonts.scss
scss formatting
Merge pull request #3564 from guardian/new-comment-font

New comment font & tweaks