Auth "magic_word" should support regexes

[nosmo]

Simple PCRE ones, so that we can say "^/mysecretpage" and so that we can avoid matching "news/story-about-mysecretpage".

[kheops2713]

Commenting just to bump this feature request. It can be useful for what nosmo underlined but also to set several specific paths e.g. (^/adminpath1|^/adminpath2). What I have in mind is that Wordpress, for instance, has /wp-admin and /wp-login.php.