features/changelog: barrier all entry creation fops

when a snapshot is taken, there are chances of entry creation fops
not being recorded either in changelog or through the recursive
ancestry xtime updation by marker. This causes consumers of changelog
(primarily geo-replication as of today) to not be aware of these entries
after a snapshot is restored. This can lead to inconsistencies. This patch
is an interim workaround to barrier creates till changelog becomes completely
crash consistent.

BUG: 1138952
Change-Id: Idd5e690a05fe2c7c5d32d1541a0d9b5132881ea7
Signed-off-by: Vijay Bellur <vbellur@redhat.com>
Reviewed-on: http://review.gluster.org/8517
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: ajeet jha <ajha@redhat.com>
Reviewed-by: Aravinda VK <avishwan@redhat.com>
Reviewed-by: Kotresh HR <khiremat@redhat.com>
Reviewed-on: http://review.gluster.org/8646
features/changelog: Removal of redundant fop color count while draining.

BUG: 1138952
Change-Id: I594be0d09c6af2e4a34da3e819d1ab6fd85e34c4
Signed-off-by: Ajeet Jha <ajha@redhat.com>
Reviewed-on: http://review.gluster.org/8542
Reviewed-by: Vijay Bellur <vbellur@redhat.com>
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-on: http://review.gluster.org/8647