Update CHANGELOG.md

Include changelog from previous release.
add replicaset support to mongodb_user module
re-add idempotency check
Modified Cron to add AIX Crontab support, changed according to suggestions
from mpdehaan and redone entirely.
Merge pull request #6870 from MorrisA/devel

Modified Cron to add AIX Crontab support
moved ebs_optimized param out of main request hash
Simplify node matching
Merge branch 'rax-clb-nodes-nodeid' of https://github.com/sivel/ansible into sivel-rax-clb-nodes-nodeid
Adding bold to service doc to call up state and enabled.
Fixes #6845 evaluate changed_when only if task is not skipped
Revert "Fix #5679 again after recent changes in core"

This reverts commit 2bfaacd17063ed52ceca53f55861acb7ff655c66.

Fixes #6821
Fixes #6780 Update version_added for source_dest_check in ec2 module
Merge pull request #6883 from ericlake/devel

Adding bold to service doc to call up state and enabled.
Merge pull request #6869 from cove/mongodb_user

add replica_set attr to mongodb_user module
Merge pull request #6850 from atlashealth/ec2_set_ebs_optimized

ec2: added ability to set EBS optimized instances
Fix version_added for url in airbrake_deployment module
Fix version_added for a few parameters in django_manage
Set version_added for snapshot in ec2_vol
Fix version_added for new params in gce_lb
Fix version_added for new params in gce_net