SHELL32: cleanup, create unicode versions of some functions

[Mike McCormack]

Alexandre Julliard wrote:

> Actually the right way to get rid of them is to convert to Unicode. In
> the few cases where we actually have to work with Ansi characters they
> will most likely be in the Unix codepage and then switching to
> lstrcmpiA would be wrong.

I'm on the way to converting some of the shell32 code to unicode, so the 
strcasecmp instances in there won't be round for too long.

Mike