Makes it easier to clean any unwanted sites

* No more if.
* Allow lookup to set default value for all docroot
* updated pillar.example

unless test -d on file.directory seems useless.

Support for DocumentRootUser and DocumentRootGroup

Detect runtime, rather than before starting/installing anything.

Templates already fallback to SiteName before site id.

This attemps to be consistent with them, and avoid having to explicitly specify
the DocumentRoot, when the template already does the proper inference.

(We were only supporting 2.4 anyway.)

This reverts commit 429039819d.

in pillar add 
RedirectMatch: true

Adapted log format to Apache's new default

Other states in this formula allow changing the Apache httpd or module
package on RHEL/CentOS, e.g., one may use packages from the httpd24
SCL to install newer versions than in the base repositories.  This
changes the apache.mod_ssl SLS to match them.

Including optional per-OS templates

(Solves https://github.com/saltstack-formulas/apache-formula/issues/153)

CentOS 6 reports as CentOS-6 rather than CentOS Linux-6 from osfinger grain