The caution message before indexing is revised (a cosmetic change).
The variations of the parameters to changed_when: now unified to False.

Previously, there are "no", "false", and "False" used for changed_when:.
This is the bugfix of the package dependency for CentOS7.

Git was missing for CentOS7 minimal installation.  Also mod_perl had to be taken from EPEL7 for CentOS7.
Httpd reload is moved from handlers to tasks of 170-setup_httpd_RedHat.yml.

A handler is fragile, because it is run at the end of playbook and it will not be called when the playbook exits for some error.  The second run of the playbook might not send a notification to the handler, because the configuration is already changed before the last error.  Thus, reloading httpd in a task is more certain to be called.
Some annotations are added for 110-tweak_os_RedHat[67].yml
Reloading iptables for CentOS6 is moved from handlers to tasks and enhanced.

Handlers are fragile.  Now, reloading iptables is run whenever the current state of iptables does not contain the ACCEPT rule in INPUT chain.
This opens httpd_port both in the current state and the config of firewalld.

Previously, the current state of firewalld is updated by the "reload" handler.  However, this does not work when the new open port is added to firewalld ("restarted" in place of "reloaded" would have worked fine).  The new way is not to reload the config file at all, but is to let firewalld module to change the runtime state with permanent=False.