Web access for cronjob and further fix for old libxml.

I've modified the cronjob to be available from the web too (so one can use an external service such as webcron.org).

~~I've also added another fix for the old libxml bug. In my case unbreakable spaces were decoded as "a0" instead of the correct "c2a0"; throwing an "incorrect character" error.  It might be needed only for some php versions but I don't think it would create any problem if it runs while not needed.~~ Please do not pull this commit (a4d8589). It only partially fix the problem, I've found a real, clean solution, will post it tomorrow.

My first time messing with github, my apologies if I did something wrong.