Add user-defined envvars

According to the pillar.example file there is no site.ProxyPassTarget,
so ProxyPassReverseTarget should default to proxyargs.ProxyPassTarget
(ie. site.ProxyRoute.ProxyPassTarget)

If MaxRequestWorkers is greater than 256 than you also need to set the
ServerLimit value which is defaulted to 256 but has a 20000 hard maximum

* Adding exclude_listen_directive option

* Updating Debian config

Do not force usage of apache.config in apache.vhosts.standard

* RedHat: Made AddDefaultCharset Directive configurable

* Added description of apache:lookup:default_charset to pillar.example, sane default equals former hardcoded UTF-8

In 4d04d95b02 (#113)
apache/vhosts/standard.sls has been modified by @genuss to include
apache.config on the basis that apache.config was now able to retrieve the
interfaces/ports from pillar data in apache:sites.

I use apache:sites to register virtual hosts with non-standard
"template_file" (they contain the desired configuration directly)
and the "interface/port" keys are thus not meaningful.

apache:
  sites:
    example.com:
      template_file: salt://vm/example/apache-vhost.conf
      DocumentRoot: False

The generated ports.conf ends up containing only "*:80" while
my virtual host configuration files need ports 80 and 443. The
situation was perfectly fine up to now because the default configuration
file handles both of those ports if you have mod_ssl installed.

People who want to use apache.config should just explicitly include
that state, we should not force its usage to all apache.vhosts.standard
users.

* Add ProxyRequests directive

This allows or prevents Apache httpd from functioning as a forward proxy server.
[See](https://httpd.apache.org/docs/current/mod/mod_proxy.html#proxyrequests).
The default action is off so I've set this a the default for this formula so it does not change the default behaviour.

* Add example pillar usage

* Add support for proxy pass target options

* Add example usage

Proper disabling of the default vhost

enable mod_ssl on Redhat

Removing the file /etc/apache2/sites-available/000-default.conf leads to an error when Apache is restarted.
So the symlink in /etc/apache2/sites-enabled/ should be removed, the actual file can stay.

Add custom port to RedHat config

Add mod_security management

Add gitignore, kitchen-ci files
Add some tests and documentation

RedHat: Added configurable variables, Fixed bug if vhostdir is something diff…

Add support for name based virtual hosts

rename no_default to no_default_vhost (matching README.md)

Add support for Ubuntu 12.04

fix Options in pillar.example

Fixed directory typo for logrotate in pagespeed mod.

fix line feed suppression in standard.tmpl

#125 activate ssl module

Fixed a bug where the Require parameter would be on the same line as …

Added the ability to remove the vhost file from debian

- This is then ignored by Apache

Manage ports.conf file properly

Cleanup whitespace in generated vhosts

Correct handling of allow encoded slashes

Allow to configure several interfaces for a vhost.