Lightened color of icons, minor edits to templates

+ Made Font Awesome icons lighter color (dark gray instead of pure black)
+ Modified bootstrap/templates/archives.html
  + Reversed sort order of year and month
  + Removed bullet points from unordered list
+ Modified bootstrap/templates/tags.html
  + Added header "Tags" and a <br/> after it
  + Removed bullet points from unordered list