Setting some common ssl declarations. Set up so that when the default value (from http://httpd.apache.org/docs/2.2/mod/mod_ssl.html) is given, the declaration is omitted from the vhost configuration.
missing an o in protocol
Declare the public certificate and private key.

Some clever has to be put around this as the keys could be:
- previously defined and uploaded as a Puppet resource
- installed as part of a software package and not defined as a Puppet resource
- may not exist

I'm sure other scenarios will come about.
This should now add CA and CA chain certificates to the SSL declarations
Updated README.md to provide documentation for the new SSL functions in apache::vhost class.
downgrade fail to warning for not providing certificate and key locations

Updated README.md to be clear about requiring certificates and keys.
Merge branch 'vhost_ssl' of https://github.com/nesi/puppetlabs-apache