switch from sass to style as preprocessor

package.json

scss/_colorMixer.scss

scss/_var.scss

scss/style.scss

styl/error.styl

styl/lib/_colorMixer.styl

styl/lib/_comments.styl

styl/lib/_content.styl

styl/lib/_cookieinfo.styl

styl/lib/_footer.styl

styl/lib/_general.styl

styl/lib/_header.styl

styl/lib/_home.styl

styl/lib/_menu.styl

styl/lib/_menuMobile.styl

styl/lib/_mobile.styl

styl/lib/_mobileSmall.styl

styl/lib/_normalize.styl

styl/lib/_ntp.styl

styl/lib/_prism.styl