Convert back to icon fonts

[cferdinandi]

Update approach for lighter CSS and better markup.

// Base class for all icons
.icon { ... }

// Icon content
.font-face .icon-twitter:before { content: "\e600"; }

// Icon colors
.icon-twitter {
    color: #0088cc;
}

// Hover effect in link
a:hover .icon-link-wrap {
    text-decoration: none;
}

a:hover .icon-link {
    color: darken( $color-primary, 15% );
}

a:hover .icon-link-text {
    text-decoration: underline;
}

// Inherit color
// (Only needed for overriding colored icons)
.icon-inherit-color {
    color: inherit;
}