quickfixed contact and app icons
added Git link
rearranged home css
Merge branch 'develop' into fix-13sprites

Conflicts:
	core/styles/all.css
	core/styles/tools/_translucent.less
	core/styles/typo/doc/_body.less
	home/home.css
	home/home.less
simplified icon mixin
updated styles
added symbols to logic and set theory
updated titles of binary relations and operations
deleted TODO in /blog/
Merge branch 'develop' into feat-36punct

Conflicts:
	blog/semantic-punctuation.html
Merge branch 'develop' into feat-37ent
added parens, brackets, braces, and lt/gt signs
added apos and quot, moved lt/gt to relations
moved quotes to new section
added some math symbols
reorganized groups
fixed link to _headings.less
untabbed /_includes/ and /blog/
untabbed /core/doc/, /core/images/, and /core/scripts/
untabbed core/styles/