Fixes by NY

[Nijikokun]

Url disputing: well urls should only be alphanumerical only. since it uses that for slugs I would assume that.

What with IDN and the way today’s OS work with Unicode even in file names I think that way of thinking is a little old fashioned. One thing I could find myself agreeing with is to ban certain forbidden signs like slashes and colons and send those directly to the 404.

It is old fashioned but php's native support of them is a bit rough and takes a bit of functions to regexp. I personally know the regexps for japanese / some latin fonts and thats about it. I do agree with banning forbidden signs though.