[syslog-ng] [PATCH (3.5) 3/3] template escaping changed

[Juhász Viktor]

template_escaping: template and correlation index escaping changed.
    
correlation index escaping introduced, because it's a correct use-case,
that somebody want to use @ character after template, in this case use '@@' after the template
e.g.: ${USERNAME}@gmail.com caused bad behaviour
        and there wasn't any possible solution to reach the correct behaviour
        from now the correct usage is: ${USERNAME}@@gmail.com
    
The template $ escaping changed from '\$' to '$$'\
because it was very confusing that the lexer could process '\'  and the template_compile processed '\' too.