Fix check for SSLCertificateFile, SSLCertificateKeyFile variables in vhosts/standard.tmpl, now using dict.get()

Add optional templating for the register site aspect of a pillar.

User can specify keys to be included as defaults, otherwise it is
treated as a normal managed file.

- Adding confext to virtualhost names.
- Renaming the default config file for Ubuntu (000-default.conf).
- Adding ability to use "Require all granted".

The structure of this example file was quite confusing. Most of these
values are not required and should be denoted as such. Jinja notiation
to denote re-used Pillar values was also a bad and confusing choice.

Closes #8

Having multiple different examples in the same file was causing
confusion.