add gem
add jekyll asset pipeline plugin
remove IE <8 compatibile CSS. Please upgrade to The Internet Ultimate Edition for Enterprises NT
move preprocessed css and js to source/_assets
deleted old assets folders, converted css to jekyll_asset_pipeline
convert js to jekyll-asset-pipeline, add less preprocessing
finish conversion to jekyll-asset-pipeline
update readme
Merge pull request #335 from sendgrid/jekyll-asset-pipeline

Jekyll asset pipeline