Fixed issues and added new scripts to urlify.js

Added the following scripts:
* Lithuanian (thanks to petraszd for the patch)
* Serbian (thanks to offy)
* Azerbajani (thanks to Ali Ismayilov)

Fixed the following issues:
* In Polish character map, some uppercase letters were
  converted to a lowercase ascii equivalent.
* The letter Y with a diaeresis had a lowercase version but no uppercase.

The code was also simplified and cleaned up:
* Use of `var` statements everywhere
* Systematic use of semicolons
* Proper looping over arrays and objects.

Thanks to @oinopion for his help in getting the javascript
into proper shape.

Fixes #8561, #11035.