Bump version to 5.6.3 in the 5.6 branch

Cherry-pick elastic#5189 to 6.0: cms_get and cmd_set mixed up in memc…

…ached module (elastic#5233)

Cherry-pick of PR elastic#5189 to 6.0 branch. Original message: 

I just created this here and thought to look at the code.

https://discuss.elastic.co/t/metricbeat-memcached-module-seems-to-mix-up-memcached-stats-cmd-get-and-memcached-stats-cmd-set/100732

[DOCS] Update link to certgen command

Bump version 5.6.1 (elastic#5151)

Close changelog for 5.6.0 (elastic#5098)

Close changelog for 5.6.0 (elastic#5098)

Add Cloudfrontbeat to the community beats (elastic#5025)

Fix doc for target field at decode_json_fields (elastic#4845)

The target field is treated as omitted if the value is empty. Decoded fields are placed under the root if the value is the empty string.

Update info about loading dashboards and index templates (elastic#4778)…

… (elastic#4818)

Update Auditbeat docs with changes from testing

Cherry-pick elastic#4658 to 5.5: Normalize times to common.Time with …

…UTC time zone (elastic#4683)

* Normalize times to common.Time with UTC time zone (elastic#4658)

During event normalization convert any time objects to a common.Time and ensure that the time zone is UTC.

Fixes elastic#4569
(cherry picked from commit 29f4cc7)

* Fix changelog