[Cppcms-users] Update "generic_filter" patch

[Joerg S. <jo...@be...>]

Hi Artyom,
this is a slightly extended version of a patch I send you a while ago.
This includes an actual test case now. The goal is to make it easier to
use the template framework for non-HTML output. For this purpose, a view
can use the new arguments to override the default filter. There is one
issue in that the static parts of a URL expression can't be quoted,
which is difficult to work-around with more intrusive code changes. As I
generally don't use the URL tag in non-HTML output, it doesn't matter to
me.

Joerg