LUDOC-435 quotas: Update project quotas requirements

LUDOC-435 quotas: Update project quotas requirements

This patch adds specific notes in the project quota documentation
to explicitly state that a patched server is required and that
patchless servers do not support project quotas.

The patch also removes the quota enabling instructions for Lustre
versions older than 2.4.

Signed-off-by: Joseph Gmitter <jgmitter@whamcloud.com>
Change-Id: Iaaa602012b244c225605ffe458e63634a7f9e40a
Reviewed-on: https://review.whamcloud.com/34516
Tested-by: Jenkins
Reviewed-by: Wang Shilong <wshilong@ddn.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>