remove sass plugin loading

Signed-off-by: Gaetan Semet <gaetan@xeberon.net>
Give a try on sass

But bootstrap is not supported, so we go back with the
browser incompatibilities/miscrafting issues.

Signed-off-by: Gaetan Semet <gaetan@xeberon.net>
Revert "Give a try on sass"

This reverts commit 6b1baf95e0514d41ef49c1b27ea5934347224f79.
Readme on reason why not to use Sass

(Thanks to Git, the patch is still in conf, sha1 is
6b1baf95e0514d41ef49c1b27ea5934347224f79 and has been simply
reverted)

Signed-off-by: Gaetan Semet <gaetan@xeberon.net>
pretty html generation and prod/dev targets for less

Signed-off-by: Gaetan Semet <gaetan@xeberon.net>