Updating board page header classes

Updating classes to make styling a bit easier
Updating styles on Home and Board views

updating Category caret formatting
indenting boards list
deemphasizing headers on Board view
Updating Board view styling

updating colors and spacing
updating look of Start New Thread button
updating section borders
Updating link colors

Starting to move all link colors to $color-active sass variable
Easier to change link colors / brand site
Changing background color of Boards page board title

lightly colored background on Boards page to highlight title and
pagination