Images optimized in CodeKit

Signed-off-by: Ralf Koller <r.koller@gmail.com>
Compass config file added

Signed-off-by: Ralf Koller <r.koller@gmail.com>
Intrinsic ratio added for images alongside the move to the Scss syntax

Signed-off-by: Ralf Koller <r.koller@gmail.com>