add possibility to define variables inside VirtualHost definition

[trefzer]

The variable can them be used inside the vhost tag as a variable.
At the footer, the variable is undefined to avoid side effects
in other vhosts.

also see https://httpd.apache.org/docs/2.4/mod/core.html#define

[tphoney]

Hi @trefzer thanks for the PR. this indeed looks like a useful addition to vhost.

• $define does not feel like a good variable name
• definitely needs example usage, along with the text you provided
• an acceptance test showing that it works as intended.

Thanks again for this. Have a good one !

[trefzer]

@tphoney
I agree, that $define is not optimal, but it's the same as in the config file which make's it easy to read. But I did not find any better name, I'm verry open for suggestions.

about examples, I think the link in the apache docs is quite clear. But I can add a simple example.

[tphoney]

A fair point well made, i have to ask :)

Thanks for the great PR, have a good one !