[dwm] dwm is simple again

Hi there,

I pushed my changes into hg tip, and ask you to test and review
it!

I removed about 100 LOC (yeah!).

Now dwm does not contain NMASTER and VRATIO anymore. Same with
inc*() functions, they have been removed.

I added const char * as argument to arrange-functions. Use them
instead for special things in the future. Due the nmaster
removal I simplified tile() somewhat, I believe it can be
simplified further. HRATIO is call MASTER now, and defines the
master width (0.1 .. 0.9 means 10% .. 90% of waw).

Due to the fact that a layout function is bound to shortcuts
now, it has to be made global, see config.*.h for details.

Also note that following check should be included in any
arrange() function:

        if(lt->arrange() != <your_arrange_function>)
                return;

So if everything works well, I'm going to release dwm this
weekend.

Regards,

-- 
 Anselm R. Garbe >< http://www.suckless.org/ >< GPG key: 0D73F361